When I started coding on the Amiga there was no help at all so fucked if i'm helping
If you want to learn, then get AsmOne. It's better than Devpac and was created (or rewritten depending on your view) by Promax/ex-Kefrens.
Books wise, there is no substitute for the ROM Kernal Reference. There are lots of books floating around on www.ebay.co.uk
To get you started off, save the Coding Tutorials from LSD Grapevine magazine. They are excellent.
Another resource is Aminet. Lots of source there, including the source to Alien Breed.
Not sure on web sites. Programmer's Heaven has an amiga section at http://www.programmersheaven.com/zone20/index.htm
Lots of stuff for you to start off with. Just be prepared for a lot of trial and even more (guru) errors.