ESO is an MMO. As such, it changes with every patch, sometimes dramatically. A guide to ESO from April 2014 would be utterly worthless today. A guide from August 2015 will likely be outdated next year too. Your best bet are frequently updated online resources like wikis, known youtubers etc. Of course, if you have specific questions, feel free to ask on the forum. There are several PvP guides floating around here, for example.