Does anyone know of any After Effects plug ins or presets that are free for me to use which would be essential for me to use for editing?

Thanks in advance!
DigiRoots

Well.. After Effects isn't for editing... But here's some link love:

http://videocopilot.net/presets/
http://xscriptorium.com/
http://aescripts.com/
http://www.redefinery.com/ae/
http://aenhancers.com/

And of course we can't forget Adobe's own resource:
http://www.adobe.com/cfusion/exchange/index.cfm?event=productHome&exc=21&loc=en_us

None of these are really 'essential' by any means, but some useful tools that help with day to day comping & motion graphics are:
Zorro the Layer Tagger (http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1694092)
Magnum the Edit Detector (http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1387519)
TrackerViz (http://aenhancers.com/viewtopic.php?f=3&t=1070)
Kuler Browser (http://www.adobe.com/cfusion/exchange/index.cfm?event=extensionDetail&loc=en_us&extid=1896024)

Thank you Will! I know I miswrote that post on "editing". It's more like compositing. Thanks again!

P.S. Video Copilot is amazing! Go Andrew Kramer.

AE 3way color correction free.. (Will pointed me to this..)

http://prolost.com/blog/2005/6/16/three-way-color-corrector-in-after-effects.html

Thank you for that!