A lot of players know about this but I was surprised to find out how many didn't.  So I am posting for anyone who doesn't know.  There is a way to get exp for your char while afk and I am providing a little guide to.  Anyone please add what I miss or mess up!

Requirements:
First you have to be lvl 21 or over.
Second You have to belong to a nation.

Each nation has their own Master from whom you can study from.  When you are sitting and the little yellow chinese words stream up from you, you're studying or gaining exp.  The streams of words must be coming from your char or you will not be gaining exp.  To start the process you have to talk to the NPC that you can learn from.  In Qin the name of the NPC is Lord Bradford and when you talk to him you chose the option to learn from him.  It is similar for other nations I imagine.  If you don't know the NPCs name, look for players sitting around with streaming letters coming from them that is the NPC.  

I believe you can only study from your nation but to be honest I haven't test it out.

When the letters are streaming up from you, you'll see a orange number appear above your head.  That happens when exp is being given to you.  The exp isn't given continuously but shows up every few seconds.