Is is that time of the month again? I imagine all of you are prepared for the festivities! Where is it? A closely guarded secret of course! I suppose you want to know, huh?
Just south of Shatt in Shadowmoon Valley, if you look at your map, it's on the upper right tip of the Stattrath City scroll. Ok. Now I imagine you are expecting me to tell you what to do while visiting there? Ok. Here goes:
Depending on if you are a buyer or seller (I recommend the latter, or "flipping") the items in the AH, here's my quickie list that I use to search for the items needed to get your Darkmoon Faire PrizeTickets from the fair. Now there isn't much of a markup for the "turn-ins" with the tickets, but you might want to look at your server, as the prices fluctuate almost hourly. Your best bet is to flip the items for a better profit IMO. 
There are a few vendors within the gates of the faire, one has very low level herbs (watch your AH price, as the Fel Lotus and Living Ruby are probably not a good deal, but the rest are. The other vendor has scrolls for sale (once again, not a huge markup, but if you are willing to spend 2s to get 30s, then take advantage- great for low level toons btw).
Now the vendor that you are gonna want to hit is this little ogre "kid" running around chasing his frog. His name is Flik. Hop on your mount, and just look for this demon running around like he just popped some speeders. If you mouse over him (with your cursor), he will stop. He has the good stuff for sale. Too bad they don't stack, but worse case, buy a few of the Tree Frog Box, and mos def pickup the "limited" Wood Frog Box. Now the good thing about these is they sell quite frequently. Thats my quick rundown on the Faire, if you feel I left anything out, don't hesitate to leave a comment below to help the other readers. Been working on another post, will hopefully get it out to you this afternoon, so keep posted!