What are you looking to learn? That may help folks suggest guilds for you.

I am guildmaster of Lone Wolf Help that started (and still is) a guild for solo players who are looking for help sometimes, but it has turned into a very active, fun, social guild. We are mostly geared towards PvE, although do partake occasionally in PvP (although not serious). We started back in May 2014 with many members still active from then, so we definitely have quite a few vets in the guild that are knowledgeable about many aspects of the game. We are more a casual guild though, so if you're looking for a competitive end game guild we may not be the best fit for you. Although end game events are something we have been looking into. You can contact @Nestor or myself if you're interested in joining, or have any questions!

Good luck with finding the perfect guild for you!