The repos have pretty straight forward submission links/processes so each website will have details on how to submit to it. If you ae unsure about something you will always be able to email the owners.
MyRepoSpace - If you want a private repo where you can manage everything by yourself, good for beta testing.
BigBoss - Is a default repo.
ModMyi - Is also a default repo, although I don't have much experience with hosting here it seems as good as BigBoss.