get yourself 2 packs of zig zag and some italian seasoning. it's hard to describe how to roll but i can give you some tips that changed the way i roll.
never EVER worry about the stuff falling out the ends. more people fuck up their joints by focusing on silly things like crumbs when they should be focused on rolling. you can work on keeping the herb in the paper later. if you need to, start out with more herb than you'll need if you always knock a bunch out.
once you've placed the herb in the paper, focus on spreading it as evenly as you can before you start rolling. if you knock stuff out a lot like mentioned above, ovecompensate by overfilling the ends a bit.
i think the part where most people fuck up is the "sealing" or sticking the paper. when i first "managed" to roll decent joints, what i would do is stick the paper in the middle, and then tear on each side of where i stuck it to form two "end flaps", and then stick the ends one at a time. this helped me to get the ends tighter if you can get a visual of what i'm describing (stoned, sorry).
joint rolling is a lifelong work in progress. as long as you can find a way to get consistant smokable results, you will get better without even trying.