When you are installing the roof over your patio, you need to determine where you want it to be attached to your home. Keep in mind that it will slope down as much as two feet, so you will need to accommodate for that when you measure.
In your instruction kit, you should find a track that connects to the home and you will put in in the location where you want to have the cover end. Make sure that you use a level so that it is even all the way across, then mark it well, and drill all your holes beforehand. Then you can put the track on with the included wood screws, making sure that it is level while you do this, and caulk it in place to make it look nice and give it extra hold. Next, you need to measure all your pieces that form the cover. They should not be much more than two inches longer than your patio itself.
Now you need to know how high you need to make it. You also need to know whether you want your posts to be on the patio concrete or in the dirt surrounding it. If you choose the latter, you will need to add a couple of extra feet to account to the depth that the post needs to be. The top of each post should have a tilt beam placed into the grooves at the top so that the patio covers can be easily adjusted.
When the whole thing is put together it should stand upright. If you have installed the posts in concrete, then you should just easily screw the posts into the brackets. However, if they are going into the ground, you need to dig your holes two feet deep and fill them with concrete and drop the posts in. Make sure that the concrete is completely dry before you move on with the project.
When the posts are up and the concrete is completely dried, you can attach the cover posts to the patio. If you measured right, they should match up exactly with the header rack and the tilt beam. Once you have made sure that everything matches up, you can fasten all the pieces together. You may find that your panels are too long, but they can be trimmed so that they fit just right.