I watched a 45 minute Youtube video by Terry White about the top 10 things people want/need to learn on Photoshop. During the video I took notes and paused it after each section to practice. A lot of the big things he talked about I learned last week: cropping, creating layers, moving and removing objects- it was a great review though.
In order to do this new skill of combining photos, I practiced taking part of a photograph and putting it on a new background (another photograph). The first thing you have to do it open up the two photos on photoshop with two different tabs. Using the move tool, you take one photo and drag it into the other photograph. Then you use "free transform" to resize the photo. Next, you want to select the part of the photo you'd like to use. You can use several tools to do this, but I used the quick select tool that looks like a paint brush. You have to be careful when selecting (that's where having a mouse would have been helpful) because you don't want to get other parts of the image that you don't want. You will see this on my photos below.. I was not precise enough and you can see some of the old background around the people.