Are you looking for a complete description on how to build a Sharepoint Development Environment? well, look no further Eli Robillard has done a very complete article on how to build this. I would like to point out to a very important detail in his article:
“The configuration described here is intended for a good laptop, which today is limited to 4Gb RAM. If you have 4Gb, give the virtual machine 2Gb. If you have 3Gb, give the virtual machine either 1.5Gb or 2Gb. If you have 2Gb or less, buy more RAM or host your virtual server elsewhere. Seriously.”
This is a very important detail because unfortunately from my own experience working in a 2Gb RAM virtual environment or less is really a pain . . .
You can find this article here.