STICK WITH AWDWR but if you really want to know more then read on....
Well Programming Ruby 1.9 (AKA the pickaxe book also from the pragmatic bookstore) is the next one to get. This with AWDWR are the definitive books for anything to with Ruby and RoR and will quickly become your bibles. You don't need the programming Ruby book just yet but I'd recommend getting it ASAP. It's more of a programming guide for Ruby than a tutorial and is not a book for beginners but as soon as you start asking how to deal with array's, hash's File I/O, RegEXP (The list goes on and on...) then that's the time to start looking at the Pickaxe book.
PLEASE PLEASE PLEASE Read the WHOLE AWDWR book and not just the Depot app bit. A mistake a lot of people make is to code the depot app as they read and then never look any further when in fact the Depot app tutorial is only half the book and only half the story. You'll benefit hugely from the rest of the book.
Any other books will largely depend on what you really want/need to know about programming in general, database design, UML (Unified Model Language for OO software design), ERM (Entity Relationship Modelling), the list goes on and is HUGE but by the time you realise you want to know more you will know what it is you need to know about and then you can ask for recommendations on what book to get for specific subjects.
Having said that, Martin Fowler has published a lot of programming concept books and is generally well regarded.
But seriously, you have an awefull lot to get your head round and you are going to be on such a massive learning curve that AWDWR will keep you going for the next few months and proabably longer if you decide to re-code the depot app a few times just to get familiar with everything (Well worth doing this. I have 20 yeears programming experience in a large number of languages (Ruby and RoR are my favourite) and it took me 3 iterations of the depot app to get confortable with the environment).
If it helps as a starting point I'll outline my setup,
I have netbeans as my IDE.
I have used this under Windows XP successfully for a year after switching from Aptana Studio (AS)
AS was great when I first started until I found netbeans which is waay better IMO
I ditched windows XP last year when my HDD gave up on me. I decided it was time to upgrade but Vista and windows 7 had a price tag I didn't want to pay so I now run Ubuntu Linux very happily and miss nothing about windows at all.
Both Netbeans and AS run very happily on Linux, OSX Snow Leopard and Windows.
There are other IDE's but these are the main ones.
If you don't like the idea of an IDE (Integrated Development Environment) and prefer to work using a text editor and you are lucky enough to own a Mac then Text Mate is the editor of choice, there are clones for other OS's but I seriously recommend you get your head round Netbeans first.
I use Firefox and Google Chrome as my browser and test in each.
Get firefox and install the SQLite plugn and the Firebug plugin and make use of the right click inspect element option in both browsers (Firebug is needed for firefox but google Chrome has this already installed.)
The above is an invaluable tool for working out styling etc... as it gives you live editing effects.
I use Capistrano for site deployments (Also covered in AWDWR) I use git as the ultimate version control system and host on both github and sourcerepo (google them) and I can highly recommend RailsPlayground (Again google them) as a host when you are finally ready to move your app into the real world.
I use both SQLite3 and MySQL, you don't need MySQL on your machine as SQLite is more than adequate for development purposes but it will help you immensely when it comes to hosting if you get familiar with MySQL sooner rather than later as it will undoubtedly be the DBMS that you will use in production.
I won't cover the ones I need/use except to mention that I use JQuery in preference to the built in Rails AJAX stuff for AJAXifying my websites.
AWDWR Deals with Rails, pickaxe deals with Ruby but neither deal with HTML and CSS.
You will find the W3Schools site invaluable for this as you have to learn about styling your HTML (colours, layout, font's and a million other things).
It's a totally ridiculously huge site and don't expect to be able to find what you are looking for just by navigating around so here are some specific links to point you in the right direction
The above are ESSENTIAL reading if you really want to understand what a website is and how to write one
You don't need to know too much about this for AWDWR as the very basics are covered, but you really will need to know a lot more as soon as you start your own real world fun.
That's a lot of info and I hope it hasn't given you a headache.
What you want and what you need are too often not the same thing!
When your head is hurting from trying to solve a problem, stop standing on it. When you are the right way up you will see the problem differently and you just might find the solution.
(Quote by me 15th July 2009)