Minesweeper is a tough game to master, but it is certainly learnable.
First and foremost, you must understand what the numbers mean. If you see a 1, only one mine is adjacent to it. If you see a 3, then there are three mines next to it. If it's blank- lucky you, no mines surround it. Then all the surrounding squares are automatically uncovered. If one of these is blank, the surrounding squares are uncovered- and so on.
But how do I figure out where the mines go, you might ask. Well, first you will probably need a blank square. Once you get one, you may find something similar to this:
Now, where do you think the mine is? Check the square in the corner, a 1. All the squares surrounding it are blank- except one. That must be a mine! Now, what do you do? The other squares are touching this, too. So the squares surrounding them are safe and can be uncovered.
This is the basic tactic of Minesweeper. By building on this basic idea you should be able to figure the game out. Good luck!