Here's Fley's handy software recomendations:
+ Titan Panel
http://ui.worldofwar.net/ui.php?id=1442 Very useful thing, fully customisable. Tip: To rearrange the items in the bar, just disable all of them then enable in the order you want them to appear along the bar/bars left to right.
+ Various others
http://ui.worldofwar.net/ui.php?id=1830 Here's my reccomendations for people who don't want to overdo it from this pack:
!StopTheSpam
Atlas
Auctioneer
EnhTooltip (Should be combined with Informant)
Informant
MobInfo2
MozzFullWorldMap
Stubby (required for most to work)
Titan + All it's plugins (you can turn them on/off in game accordingly)
Verifly
That sounds like alot, but they're all useful and none of them clutter the screen.
Installing Instructions 1) Extract all addon folders to your WorldOfWarcraft/Interface/Addons directory.
2) On the character login screen, select which addons you want active.
3) Don't bother with the 'Script Memory Usage' at the top, just leave that as 48.
4) Titan: Right click the bar/bars to fully customise.
5) MobInfo2: Type /mi2 to customise.
Note: All that !StopTheSpam does it prevent the addons from showing their '___ loaded' message when you login. It's not important that you need to see them, so I reccomend enabling this if you use more than 5 addons. It just gets a little annoying otherwise.