I frequently use yumex, which is a graphical front end for yum. I like it because it lets you select pacakges and see their size (along with dependencies) after you choose 'apply' and then go back and unselect 1 or 2 or whichever packages if you want, easier than you can using yum from a terminal. Of course if I know the package name and it's just 1 or 2 packages I just use the terminal.
Failing that, there's also the option of using the Package Manager, just go to >applications >Add/ remove software and there is a tab to search by package name, and you can select the package(s) from the list. However, it doesn't give you the package size or other details during the download and install procedure that you get with yum or yumex.
To install yumex, you can just 'yum install yumex'