Many guilds will say they are helpful, just to get you in. You see the recruiting notices go up in World chat, but unless you try them out you just don't know how well you will fit. Some guilds don't recruit at all, but that does not mean that they are out of the picture. I have found the best way is to ask in zone chat for help with a quest and pay attention to who actually helps and who just trolls. If you right click on any toons name in chat you get their info as to what guild they are with. This way you can get a feel for who is helpful and who is not.
+1
Also when you find a person that will help you , ask then questions about the game , nice ppl will answer questions and give you helpful info.
Also for the bad timing Ruisen is talking about , if they use a voice chat that you are not using and they are not reading chat ,try PMing a higher up person for help.
I help everyone I can , but sometimes miss the help request because I didn't see it in guild chat.