Im assuming hip hop so, ill help you out here.....

The snare is usually on 2 and 4 and the bass drum "leads" into the snare. Hi hats are usually a steady 8th beat pulse.

Here is a diagram (*= hit - = no hit) divided up into four ticks for every beat.

Kick...: * - - - | - - - * |* - * - | - - - -
Snare: - - - - | * - - -| - - - - | * - - -
Hihat.: * - * - |* - * - | * - * -| * - * -

That's a really boring and basic hip hop beat... notice how the Kick and snare interact... the kick sort of leads into the snare... you can make it feel a little "funkier" at times by delaying a kick hit until the 4th tick of either the 1st or 3rd beat... then it feels like the Kick is really leading into the snare.

Just goof around with the basic structure of this... add some kicks in various areas. Get an open hi hat to punctuate stuff. You could even delay the second snare hit by 2 ticks to trip up the feel a little bit.

Remember you can always change the channels around, FL studio comes with "hip hop pack" so you'll have a few diff hats and snares to fool around with, but you'll want some more...so try to find some samples and shit.....

I don't feel like going into "melodies"....its not somthin i can really just tell you.... it takes time to learn and get through your head


hope that helps
peace

envisionz