Hiya,
I'm still learning my way around the amiga but here're a few things that I found useful to use/look at:
Copy of the amiga hardware reference manual. You'll need this to understand the custom chips, and how to get stuff on screen and moving. There're some online versions here:
http://amigadev.elowar.com/The best way of learning for me has been to look at actual source. Here's a good place to start:
http://cyberpingui.free.fr/rsources.htmSome other stuff that may be relevant (although you might already have this stuff setup, if so apologies :D)
AsmPro is my compiler of choice. Has an excellent editor built in, and some handy tools for demo coding. There's also DevPac. If you're cross compiling Vasm & Vlink are worth checking out.
Piccon, great for converting IFF images into RAW so you can use them in your code
DPaint/Personal Paint, for drawing things (although I do my stuff in photoshop and covert it over to IFF on the Mac. I still need Personal Paint to tidy things up though, it's great for fixing dodgy dithering and sorting out anti aliasing :D)
Protracker, for tunes, although there are loads of MODs on the web that you can borrow ;)
ClassicWB: This is a great ready rolled workbench environment that I use on my real Amiga for dev. Lots of tools all configured and built in, makes life very easy.
http://classicwb.abime.net/Oh and Amiga Forever is worth buying, as you'll have all the Kickstart ROMs needed for emulation, plus various versions of Workbench preconfigured to test your code under. It's a reliable way of doing dev, although I still use an actual Amiga to do most of my stuff on.
There are loads of books on 68000, but tbh a few googlings would probably get you just as much info.
And of course, forums like this and EAB are an absolute treasure trove of useful info.