it depends.

mainly on the time slot the promoter/manaer allows you to use, my set is 30 minutes long.

depending what tracks i do, i could do like 4-5 songs(with talkin in between a couple of them) n spit an acapella freestyle half way through jus to add variation to the set, sumtimes ill just spit song after song, it depends how i feel at the time really.

but the best way to do ur set to keep it interesting is.

come in with sumthing that introduces u nicely n instantly gets attention n makes them want more, so obviously summin energetic, then try summin maybe abit calmer, then say a smooth joint, then bring it back up slightly, and when u end, u wanna finish your best song ever, the one that ppl remember n walk away like "damn that last song was fuckin insane, i cant get it out my head".

as for DJ's... again, just approach them... i approached my DJ, and he travels anywhere now to back me, n he is classed as one of the best in the country, won plenty of DJ championships n shit.... but he lives too far away so im havin to try find sum1 abit more local, but again its all on approaching them, professional attitude and polite... if they act a prick to u, just brush it off, stay cool n move along.... no point wasting ur time.