Google reader is probably the best RSS reader available today. Here are some tips and practices for power users (hopefully, you) to help you better manage your RSS reading time and leverage it, tweak Google Reader to use first and second level categorization, and optimize you RSS subscription list.
Use folders to prioritize your reading
At a certain point you've probably realize that it is just not possible to read all of the new items you get. One possible solution is to use folders to categorize your feeds. Once you categorized all your feeds, you can read prioritize your reading by urgency level. For example, I use a folder called 'Immediate' where I put feeds that I want to read the moment they publish something new because it is important for me to know about them as soon as possible. These could be work related or new trends, usually things that if no read within day or two (sometimes less), they became irrelevant. Other folders I use are 'friends', 'Podcasts', 'Premier Blogs', and some more. I also use a 'must read' folder for things that I want to read sometime, but it doesn't really matter when (such as family blogs or new WordPress plugins).