I have two posts related to how I photograph my work. Here is the link for the mini photo cube I use.
And this is the post for the large photo cube I use when photographing my larger paintings.
I use a Nikon D40 camera. The cubes work great indoors or out. If set up by good north lit window, you don't need to use artificial lighting. Just make sure to use a tripod so when the shutter speed slows down, your pics will still be crisp. Also, remember to set your camera back and have the lense do the zooming in to fill the frame with your painting (this will cut down on the trapezoid effect).
Here's the link for the cube:)