This ought to get you started:
http://en.wikipedia.org/wiki/Metasearch_engine
Now that you have your general architecture figured out, you're probably going to have to figure out APIs for all the major search engines that you want to search... you'll probably have a bunch of web service clients, SOAP or XML-RPC.
Then, you're probably going to have to learn J2EE so you can invoke all these clients and present the results to the user. I suggest servlets and JSP's. You probably won't need to bother with EJBs.
Hire yourself a team of two or three people, and this thing will probably rock and roll in a couple months :).