Well, even though this thread is a bit outdated and probably past its time of usefulness, everyone's being an *** so I'll chip in my two cents of actual helpful information.
First, play the kirby player a lot in 1v1s. Get used to his style and tendancies. Having a feel for how your teamate plays makes teaming with him more natural. There'll be less of you two bumping into eachother if you know how he reacts to each situation and can work around him and against the opponents.
Then, find out what stages work best for the both of you and which don't. I don't know much about which stages are advantageous for kirby, but play around with stages in friendly 2v2s with others or, if you can't find others to play against, computer teams to find out which work best. Get 2-3 counter pick stages in mind.
Figure out any common tactics that you can use as a team that play to each of your strengths. For example, if the kirby grabs->uthrow a lot, get used to the tragectory that it sends the opponent at so you can jump up and hit them with a dair to rack some damage after the throw. Get used to finishing eachothers' combos and healping eachother out if need be. One of pika's strengths in teams is his ability to get around the stage fairly fast, and come to his teamate's aid or double team an opponent before his partner can catch up.
Communication is good too. Ultimately you want to react naturally to everything your partner does and work well as a team instead of two characters who happen to share the same color.
Edit: Also, I'm surprised at the responses of what I assume are pika players. Pika is a terrible character, and yet you make it sound like kirby will be the weak link in the team. a well played kirby can be an amazing teamate with his ability to kirbycide and otherwise gimp an opponent, since he has two opponents to potentially gimp and has a little easier time pulling this off in the generally-more-chaotic 2v2s.
You guys should know best the abilities that low tier characters have and that one should not underestimate them. Last week at Cataclysm3 I teamed with a donkey kong player and preformed better than in any other team I've been in. If you don't have anything useful to say, please get the hell off our boards.