I am a student and want to do some researches on computer-controlled robotics. Can anyone tell me how can I get ready for this kind of project?

e.g. serial port -> max2xx -> 89c52 -> four limbs of robotics?

The money, size and weight will be the important factors for this project. In addition, I can't buy the kits to complete this project. Everything should be built up by myself (i.e. All the boards should be soldered and assemblied by myself).

I felt brainstorm about it. Can anyone help me?