robotics projects

You are going from a 'simple' arm upto R2D2 without a built in dwarf.

Google for it, there's loads of sites. Unless you are going to buy a kit (there are some good ones about), it's a very multi faceted discipline, mechanical and electrical engineering, a good deal of math, then there's the control, interfacing and if you want autonomous action the programming which can get very deep.

You can fill a medium sized library with books related to robotics without even trying.
Research, start simple, then build and learn and learn and build.

If you are just starting, you might want to have a play with radio control first, to get a start on the mechanical and electrical side. If it's the programming, then see if you can get a kit (assuming you have access to a PC here). Try the lego ones for a first go they do the basics quite well.

It's something I keep thinking about, but I just haven't got the spare time to give it the sort of go I'd like to.