Click the entire clip which needs to be copied to multiple locations, and then press ctrl +C and then move the CTI to the locations which you want the same clip to be placed and then press ctrl +v.
We might also like to check the help document for doing the same.
hope it helps
Welcome to the forum.
I like a workflow, where I will do my editing in one Project, until satisfied, and then Share that Timeline to an intermediate file. That file, with all of the editing, can be Imported into any number of new Projects. This article goes into a bit more info on intermediate files: http://forums.adobe.com/thread/875797?tstart=0. I do this for Intros, and Outros, that might be used many times. I have also done it for "dream" sequences, that will often get a lot of use in perhaps a single Timeline.
The Copy/Paste operation can be very useful too, but I like to separate things a bit. PrE does not allow for Sequences (think many different Timelines in one Project), like PrPro does. In PrPro, I will use that Copy/Paste function, for such an operation, but because of multiple Sequences, I can separate things, as I like to do.