Re: about clock recovery
Not sure, what your academic level is. Are you just interested in this for hobby reasons, or for your degree programs.
There are USB transceiver chips you can use for this from National and Philips. You can search for that.
If you have to do this for your thesis/project, then it is only 480 MBps for USB2. Designers are usually working in the 10Gbps and 20 Gbps range these days. so there is lots of papers available on the Xplore.
You need to first brush up on your PLL theory, since it is an integral part of any CDR. Books by Razavi, and then papers should help you.
Also check out the MIT opencourseware website for M. Perrot's notes.