Dev Environment
I am using Komodo and DreamWeaver for development.
I did try the Zend Studio as an IDE (Magento is based on the Zend Framework), and the SVN plugin for Eclipse, but didn't find either particularity enjoyable to use. I have generally found there is a little more friction than we are used to with Visual Studio. It's often easier to get things done outside of the IDE. With Magento you have to create a copy of a file you want to override and put it in a different folder, so you spend a lot of time messing around in the file system, outside of the IDE.
References
Install guide for windows http://www.magentocommerce.com/wiki/general/installing_on_windows_with_xampp_and_wamp
Good video/pdf describing templates/ui http://www.magentocommerce.com/media/screencasts/designers-guide-1/view http://www.magentocommerce.com/design_guide/articles/how-magento-builds-content
Magento is build on the Zend framework. there are afew views on here, the MVC aspect is very similar to .net MVC http://framework.zend.com/
I found it very useful to try and write my own custom module: http://www.magentocommerce.com/wiki/how-to/create-payment-method-module http://activecodeline.net/writing-a-custom-module-in-magento-detailed-walktrough/
This book is pretty good - only 160 odd pages but overs some good area.
The Magento forums are rubbish I'm afraid - no one replies to anything. It has taken me hours to figure some little things out. I would just say stick at it, the code can appear to be very fragmented, but as you get used to it you will appreciate how modular and extensible it is.
Good Blogs
http://www.westwideweb.com/wp/category/magento/