Well I cant comment on bushcraft but for medicinal purposes the best book I can think to suggest is ‘Bartram’s Encyclopaedia of Herbal Medicine’. Many of the books require you to know the Latin names of the plants but this one allows you to search by the common name. It doesn’t go into gigantic detail about the science and many of the words are also explained. It also lists herbs and diseases which are easy to search.
Another book I think is lovely is A Modern Herbal by Grieve. It has an abundance of information about the traditional uses of the herbs. There are some bigger words in it but many of them you can look up in Bartram’s. I’d only get this one of you plan to sit down and read about the trees and plants. Also you may want to get a good book for identifying the trees as Bartram’s does not cover this..
I’ll list a few trees below but I am omitting any which are contraindicated at all as those should be used under the observation of a trained Herbalist. I am not claiming these herbs cure the listed diseases, only that they can be effective in treating them. Please do not take the information in place of medical advice from a professional.
Silver Birch - Betula alba
Parts Used: Mainly young leaves and bark, also sap from leaf buds.
Harvested: In spring
Minerals: Potassium, calcium and Phosphrorus.
Main use: Improves excretion of waste metabolites from the liver and kidney. Also anti-inflammatory action.
Again in English: Rheumatism, gout, arthritis, and inflammatory skin conditions.
Application:
Tea (to be used internally or externally) 1 teaspoon of dried leaves to each cup of boiling water, infuse for 15mins and strain.
Dose: Drink 3 wineglasses worth spaced throughout the day.
Willow – Salix Alba
Parts Used: The bark.
Harvested: Collected from the young branches during spring and summer.
Main use: As an analgesic and anti-inflammatory.
Again in English: Pain, rheumatism, fever, common cold, mild headache.
Application: Simmer half a teaspoon of dried bark per cup of water for 1 minute. Allow to stand for 15 minutes and strain.
Dose: 1/2 a cup.
Lime – Tillia x vulgaris
Part Used: Flowers
Harvested: Early summer
Main Use: Diaphoretic, hypotensive and spasmolytic.
Again in English: Mainly hyperextension, varicose veins, insomnia, restlessness, skin conditions and fevers. Also catarrh, coughs, colds and migraine.
Application: Add 1 teaspoon of dried flowers per cup of boiled water. Allow to stand for 10 minutes before straining.
Dose: One cup at a time. Max 2-4g three times a day
Elder – Sambucus nigra
Part Used: Flowers in early summer or berries in autumn. Inner bark spring before leaves appear. Leaves in spring.
Main use:
Flowers - Diaphoretic, diuretic, anticatarrhal, anti-inflammatory.
Bark and Berries – Laxative, anti-inflammatory, diuretic.
Leaves – Anti-inflammatory, diuretic.
Again in English: colds, sinusitis, feverishness, lung congestion, coughs, constipation. Also rheumatism and sciatica.
DO NOT EAT THE BERRIES RAW in large quantities they will cause nausia and vomiting.
Vitamins: Fruit very high in vitamin C.
Minerals: Flowers rich in minerals especially potassium.
Application: Flowers can be eaten raw. Berries should be boiled and best served warm.
Theres loads more but I've run out of time. Also theres all the plants too. Let me know if you would like any more information.
Charlotte
Buckshot is from Oxford too and a few others so we'll post it up and see what happens. 
