There are guide's for shield and armour tanking for PvE and PvP in the site's below plus many more guide's.
http://wiki.eveonline.com/en/wiki/Category:Guides http://wiki.eveuniversity.org/Main_Page

Some usefull link's.
http://wiki.eveonline.com/en/wiki/Crash_course http://wiki.eveuniversity.org/Tips_and_Tricks
I recommend using a Damage control module where possibile to boost all shield/Armour and hull resist's (you can only have one activated so it's pointless to add more than one of this module).
http://wiki.eveonline.com/en/wiki/Category:Guristas_Pirates_Sites
http://wiki.eveonline.com/en/wiki/Damage_types
Main Damage type's to protect against and to shoot at the NPC enemy's
Angel Cartel/Thukker Tribe - Explosive
blood raiders - Electromagnetic or thermal
Guristas - Kinetic
Mercenary - Thermal
Mordu's Legion/Sepentis - Termal or Kinetic
Sansha/Rogue Drones - Electromagnetic or thermal
the syndicate - Kinetic or Thermal