1) Try the Handbook, it explains the basics, and also there are basic books for sale at the merchants. You won't however find recipes for various crafts, nor do I recommend you to ask them on the forums, it's a great reason for character interaction.
2) That book should come back on your second login, it tracks your crafting levels.
3) Those skills help you customize your equipment more easily. Aside from that and roleplay value, no they do not serve a grander purpose.