I think it would be very very rare that getting a new bf or gf soon after a breakup with someone serious would end up going well at all. I've had so many girls come to me asking advice after they break up and like some other guy or want the past guy back etc etc and I always am so frustrated that they don't see what a bad idea it usually is. Usually if you get someone else that quick, it's not that they're right for you at all because the "right person" doesn't magically show up immediately after you just get through ending things with someone else you thought was the right person.
Anyway as far as getting over someone, I would know logically what to tell you would help, but logic never seems to work with getting over people. I am STILL STILL STILL trying to come to terms with my breakup with an ONLINE girl from 4 years ago so I'm not exactly the best at following advice. I always know the proper advice, but I don't follow it. :) She doesn't even want anything to do with me and I keep contacting her. Dumb.
Relationship advice is usually to just realize that every good thing you think about the person... you're just "idealizing" thigns and forgetting or minimizing anything that was not good. (you as in most people, not you specifically).