Matthew,

If you scan backwards through the threads youll probably find a dozen other beginners who have asked exactly the same question as you have. Some got quite a good range of answers.

You need to get ideas from the many fighting robot websites that are around to help you decide what you want to build. My advice to you is to design it first - dont design as you build. It is cheaper to use a pencil to correct your errors, and you have an excellent opportunity to get it within the weight limit you have chosen first time around. Building robots can be expensive, so get as much as possible second-hand for your first robot. Theres a lot of excellent stuff being sold on this forum for half price or less!

Jeremy