A quick post to mention a handy little addon I found the other day: Satrina Buff Frames. In a nutshell, it lets you customise the layout, size and grouping of your buff/debuff display. Here's how I have mine set up:
Short buffs are ones lasting less than 3 minutes. I might change this at some point to "less than 1 minute". The different colouring on the debuff timers is to show their type (magic, disease, etc.). I've since changed it so the debuff name now appears above the icon, too.
Another handy thing about SBF is it can show you who's given you a particular buff (or debuff, but that's usually obvious) in the tooltip.
All in all a very useful addon!