Rubik's Cubes are easier to solve than they look. All you need to know is how to read diagrams and some terminology and you can easily follow directions to solve any Rubik's Cube.
Find a website that contains diagrams for solving Rubik's cubes. See References for an example.
Read through the diagrams. Familiarise yourself with any terminology used in the diagram labels, such as R for "turn right side clockwise."
Position your cube so that it matches the first diagram. Follow any arrows on the diagram or written instructions underneath the diagram.
Check your cube after each step to make sure it matches the cube in the next diagram. If it does not, look back through the steps for a diagram that matches your current cube state and follow the directions on that diagram. If you cannot find any matching diagrams, start over.
Keep following the diagrams until you have solved the cube.
Common terminology includes using ' next to a letter for counter-clockwise turns. You may have to start over several times until you get the hang of it.