Just like a sander, you don't want to work with the bit, because it can run away from you. It is better to climb uphill with the bit, pushing against its tendency to run away.
It is better most of the time to invest in the bearing bits, because the non piloted bits tend to burn the wood where they rest. (not at the bit but at the shaft.)
Practice Practice Practice And use lots of scrap.
If you are going to clamp your piece down, and it is smaller than the width of the shoe of the router, you will have to do some of it, then move the clamps then do the rest. Like henry said, do several light passes to remove lots of stock.
Henry's the best on the board, IMHO, take his advice.
Have fun with your new toy. Learn how to do joints with it. It's a neat toy to build shelving with, and all kinds of things.