For some more general info about homeopathy I have this post.
General Sources of Information for Choosing a Remedy:
Dosing- which potency should I use?
Boiron Medicine Finder
Boericke's Manual of Homeopathic Materia Medica (online searchable version)
National Center for Homeopathy
Learn a more advanced method for selecting a remedy
Specific Uses of Homeopathics:
Homeopathic remedies for radiation and radiological procedures (such as x-rays, CT scans)
Homeopathy and Autism
Where to get remedies:
Some of the most common and useful remedies for the types of symptoms and health challenges faced by people like me and my family:
Aconite Napellus - sudden onset anxiety and panic, fear, croup, ear infections.
Apis Mellifica (bee sting) - allergy symptoms including anaphylaxis (not to be substituted for epinephrine in anaphylactic shock, but may help while waiting for ambulance), such as redness, swelling, burning, stinging. Restless, clumsy, light sensitivity. General inflammation.
Argentum Nitricum - anxiety, OCD (compulsions and "harming thoughts"), gassiness and distended belly, conjunctivitis, hoarseness, and exhaustion.
Arnica Montana - pain and soft tissue injury, concussion, healing from surgery or dental work.
Aurum Metallicum (gold) - Depression with suicidal thoughts, hopelessness, self-criticism and self-loathing, sense of life as a burden and not worth the effort.
Belladonna - sudden onset fever, migraine, sensitivity to light, motion, or pressure; dizziness, sunstroke, insomnia (even though sleepy), swollen glands, high blood pressure.
Chamomilla - oversensitivity to pain, irritability and anger, teething pain or toothache, colic in infants.
Cina - anti-parasitic, abdominal complaints and poor digestion, sensory and emotional sensitivity, anemia, coughing and other throat problems including difficulty swallowing and choking on liquid,
Coffea Cruda (coffee) - insomnia, PTSD, feeling jittery and restless.
Gelsemium- anxiety, weakness and trembling, fatigue and exhaustion, headache, dizziness.
Histaminem (histamine) - allergy symptoms from hay fever, food allergies, insect stings/bites, etc.
Hypericum Perforatum (St John's Wort) - often called "the arnica of the nerves". For sharp, shooting, hot pain after injury, often with spasms (indicated in particular by "hot pain"). Pain from head trauma, pain in eyes and/or ears, especially if sadness or other mental changes, from shock, especially if on right side of head. Radiating neuralgic pain and/or numbness, often sudden onset, worse with weather changes. Can also treat emotional injuries and pain, depression, anxiety.
Ignatia - PTSD (with frustration and hopelessness), depression with recent onset.
Nitricum Acidum (nitric acid) - headaches, sound and light sensitivities, very sensitive and prone to reactions, weakness and trembling, muscle twitches, associated with mercury poisoning, cracked skin, sharp splinter-like pains, diarrhea, sensitive to cold, anemia and wasting in advanced disease states, bleed easily, weak and pitted bones.
Magnesium Phoshphorica - menstrual pain and cramps
Nux Vomica (poison nut tree, contains strychnine) - symptoms from over-indulgence (food, alcohol, coffee, etc.), digestive and emotional symptoms, hernia, migraine, asthma, nausea, fatigue/exhaustion, influenza, urinary tract infections (with frequent need to pee), constipation, kidney stones, gallbladder inflammation, hepatitis, hay fever, and sensitive to light, sound, and odors.
Phosphorous - asthma, bronchitis, pneumonia, tightness in chest, dry lingering coughs, deep coughs, general fatigue, weakness, irritability. Helps clotting post-surgery and with nosebleeds, bleeding gums, heavy menstrual flow.
Phytolacca Decandra - swollen glands such as lymph nodes and tonsils, heat and soreness from inflammation, reduces scar tissue and fibroids. Helps with skin conditions associated with internal infections.
Pulsatilla Nigricans - (meadow anemone aka windflower) - tends to be for women, changeable and unpredictable but also dogmatic, paradoxical in many ways, bottles up emotions, weepy, tends towards anxiety and depression, fearful. Kindness and sympathy help but also bring on tearfulness.
Rhus Tox - back pain (esp. with stiffness), arthritis, joint pain, Cervical Spondylosis (degeneration of vertebra in the neck), hernia (from weight lifting), hives (from exposure to cold)
Sepia Succus (ink from cuttlefish) - menstrual pain and symptoms, sensitivity to cold, hives (triggered by cold exposure), miscarriage, endometriosis, long term depression with indifference.
Sol - sunburn
Sulfur - hives (triggered by heat), general skin itching.
So far these notes are all in regard to classical homeopathy. There are several other forms of homeopathic treatment, one of which is the use of homeopathic nosodes. Nosodes are remedies made from diseased tissue itself or from the pathogen directly and are used when the symptoms being treated began during or following a specific illness such as influenza or Epstein-Barr Virus.
Homeopathic remedies for asthma (Antimonium Tartaricum, Arsenicum Album, Grindelia, Kali Bichromicum, Nux Vomica, Phosphorous, Pulsatilla Pratensis)
Homeopathics for anxiety (list includes Aconite Napellus, Argentum Nitricum, Arsenicum Album, Calcarea Carbonica, Gelsemium Sempervirens, Kali Arsenicosum, Kali Phosphoricum, Lycopodium Clavatum, Phosphorous)
Remedies for Panic Attacks and High Anxiety from WAPF
Also- Natrum carbonicum (insecurity with social situations; fear/panic in unfamiliar surroundings),
Top 5 remedies for depression (includes Ignatia, Natrum Mur, Aurum Met, Sepia, Kali phos)
Remedies for Chronic Fatigue Syndrome (Gelsemium, Kali phosphoricum, Mercurius solubilis, Phosphoric acid and other “acid” remedies, Scutellaria, Zincum metallicum)
Remedies for fatigue, exhaustion, sleepiness (Kali phos, arsenicum album, nux vomica, phosphoricum acidum, picricum acidum, silicea, and zincum metallicum)
Homeopathy for menstrual pain and other symptoms (list includes Lachesis, Belladonna, Cactus grandifolia, Chamomilla, Cimicifuga, Colocynthis, Magnesia phosphorica, Nux Vomica)
Also - Phosphorous (heavy menstrual flow), Sepia (menstrual problems, irregular cycles, dysmenorrhea, morning sickness, uterus prolapsed, not well since menopause)
Remedies for hernia (list includes nux vomica, calcarea carbonica, lycopodium clavatum, rhus tox, silicea)
Remedies for post-surgery - Arnica (helps bruised and damaged tissue heal), Hypericum (reduces pain, speeds healing, and prevents infections), and Opium (this addresses the side effects of the anesthesia used)
Allergy symptoms - Apis, Euphrasia Officialis (itchy, watery eyes), Histaminem, Kreosotum (itchy skin, eczema, psoriasis, edema), Natrum Muriaticum, Phosphorous (asthma), Rhus Tox, Sepia, Sulfur
Migraine - Cyclamen (beginning with visual disturbances/aura), Glonoinum (with head congestion), Iris Versicolor (with intense vomiting, nausea, or heartburn), Kali Phosphoricum (from stress), Natrum Carbonicum (from sun exposure), Natrum Muriaticum (occuring during menstruation), Bryonia (pain begins over left eye, constipation), Belladonna (pain worsens with movement, light, and pressure, rapid onset),
Digestive problems - Lycopodium (liver problems, indigestion with burping, dyspepsia, biliousness, flatulence, bloated abdomen, baby's colic), Phosphorous (nausea, empty cold feeling, heartburn, flatulent colic, ulcers). See also Indigestion and Gas
Osteoporosis and broken bones - Silicea, Symphytum, Arnica, Bryonia Alba (back pain), Calcarea carbonica, Calcarea phosphorica (promotes bone growth), Hypericum Perforatum (back pain),
Pain - Hypericum perforatum (shooting nerve pain, or from puncture or crushing wounds), Magnesium Phosphorica (cramping, muscle spasms), Oreodaphne Californicum (neuralgic headache. cervical-occipital pain, cerebrospinal meningitis), Rhus Tox (arthritis, joint pain, lower back pain)
PTSD - Opium, Kali Phosphoricum (with night terrors), Aconite Napellus (after sudden event or shock), Coffea Cruda (with trouble sleeping due to active mind)
Radiation exposure (from medical testing for example) - Cadmium Sulphuricum, Homeopathic X-ray