in my example the bottom face is blue and the front face you're working on is yellow. my directions will also be kind of step by step to eliminate different possibilities so that its easier to follow. as you practice you'll be able to do it in whatever order you please.
take the yellow/blue/orange cubie and orient it in the top left corner so that the orange side is on the up face and the yellow side is on the yellow face.
turn the up face a quarter twist clockwise.
put the blue/yellow edge piece onto the yellow face and turn the yellow face so that the piece is on the left side.
then turn the up face a quarter twist counterclockwise.
you should now have a c/e pair.
turn the front face clockwise, then the up face cc.
put the orange/yellow edge onto the yellow face and turn the yellow face so that the orange is on the right.
turn the up face clockwise.
you should now have a 2x2x1 block.
here's where it gets tricky. orient the red/yellow/blue corner so that the red side is on the up face. (REMEMBER: 1. only turn the up and front faces 2. make sure you don't break up the 2x2x1 block)
move it out of the way so that you can turn the front face without affecting its orientation. i.e turn the top face.
place the 2x2x1 block on the bottom left corner.
move the red/yellow/blue corner to the top left of the front face.
turn the front face cc
move the yellow/red edge to the left side of the up face.
turn the front face clockwise. the up face twice. front cc. up face clockwise. front clockwise (F U2 F' U F)
you should now have a complete F2L