2D game collision problems

Hey geys, I’m a long time lurker but I got stuck on a pretty big problem, so I decided to finally create an account and ask for some help for this issue. I would really appreciate it.
Anyways, let’s go right in to it shall we?

I’m creating a very simple 2D platformer game for learning purposes. To this point it has gone pretty good. I got almost all the basics in the game. I have read alot regarding collision the last couple days, because that was the feature I still had not implemented. I have created simple collision, where you shoot a bullet, and when it hits the enemy both objects removes.

But I have failed at implementing good collision for the player. What I am trying to do, is make in this case four boxes, one for every side, and for example when the player jumps on a platform object, the bottom collision box returns true and he stays on place. The code I have done so far glitch out like a crazy person. And after a few days trying to fix this problem I have not come much further then when I started on this issue.

I would post the code I have so far, but It’s on my other computer. If needed, I can post it later. But what I am looking for are some links to good articles, tutorials and so on. Because after alot of searching I haven’t found much that fits my needs.

And sorry for my bad english, it isn’t my native language.

Thanks!