I tried to do as much research as possible before jumping in but it's hard not to. Try to read as many books as you can get your hands on and talk to others that have done conversions already. I found the "Convert It" book helpful although it's extremely outdated the basic conversion ideas are still the same. Also the guys over at http://www.ev-america.com/ have some great information that they'll hand out for free just send them an email.
As much I want this to be successful I've planned for the worse. I plan to be able to reinstall the gas engine if by chance the conversion goes south. I bought a couple of plastic storage tubs, lots of Ziploc bags and a label maker. Not only will this be helpful for any parts I can recycle into the build I will be able to reverse the process if needed...lets hope not!
It doesn't take much in regards to tools to get the job done and you can buy a few things as you go if you find you don't have just the right tool. I have a good set of ratchets, wrenches, screw drivers, torque wrenches, etc. Also a floor jack or two and four or more jack stands are a must. You'll also need to rent or borrow an engine hoist. I was originally thinking I could do all this in a one car garage spot, which is possible, but two spots is just right and gives you room to move things around and not trip all over yourself.
Get the service manual for your vehicle! There is nothing worse than wasting time trying to figure out how to remove or reinstall something and it's usually time wasted in trial and error.
Get a friend to help. It's possible to do the conversion yourself but it'll be much easier if you can get some help, especially on removing or installing the heavier items.