Here is a list of many useful links that everyone should know about:

Missions: (recommended for everyone to have as a bookmark in their browser)
http://www.eve-survival.org/wikka.php?wakka=MissionReports

Very Useful Site:
http://www.justgiving.com/GrandTheftSucata (A series of YouTube tutorial videos by a HMM channel member) (needs to be OOG as a YouTube link)
http://www.evetimecode.com/
http://www.isktheguide.com/
http://eve.grismar.net/wikka.php?wakka=WikiHome
http://eveinfo.com/
http://www.eve-online-fan.co.uk/
http://www.eveonlinehome.com/
http://www.random-abstract.com/eve/
http://wiki.eveonline.com/en/wiki/Category:Guides
http://howtoeve.com/ref.html

Skills Information:
http://www.kylania.com/eve/skills.php?p=core

Ore chart:
http://eve.grismar.net/ore/full.php
http://www.eve-files.com/media/corp/wlds/roid_grid.jpg

R&D Agents:
http://eveinfo.com/cosmos

Player Guide Collections- awesome information here:
http://myeve.eve-online.com/ingameboard.asp?a=topic&threadID=437508
http://myeve.eve-online.com/ingameboard.asp?a=topic&threadID=447021

Information about levels of security status
http://www.eve-gateway.com/security-status.html

Agent Loyalty Points and Rewards
http://www.eve-gateway.com/loyalty-points.html
http://www.ellatha.com/eve/lp-reset

Agent offers/corps:
http://www.eve-agents.com/

Ship Setups
http://eve.battleclinic.com/

Mining Guide
The Complete Miner's Guide by Halada
http://myeve.eve-online.com/ingameboard.asp?a=topic&threadid=305662
http://dl.eve-files.com/media/corp/Halada/completeminersguide_ver2.0halada.pdf

Probes all types
http://myeve.eve-online.com/ingameboard.asp?a=topic&threadID=431586

To find locator agents
http://www.eve-agents.com/

POS info
http://eve.grismar.net/wikka.php?wakka=PlayerOwnedStructure

Exploration
http://wiki.eveonline.com/wiki/Exploration:_Apocrypha
http://myeve.eve-online.com/ingameboard.asp?a=topic&threadID=445716

Industrial Ships Cargo Sizes:
http://helpmymission.co.uk/shiplottery.htm

Info for what salvage to expect from different missions
http://eve.podzone.net/wsdb/

(HMM DISCLAIMER: HMM Channel cannot be held responsible for any information on any of the Links)