Hi and welcome to EF
There's a thread somewhere that listed weight aid catabolics in order of effectiveness and where people could vote. DNP came out as clear winner, but it is of course very dangerous if not used properly. As any other drug for that matter, but it's the only one that can kill you fast. The suggested dosages were along the liens of 400-600mg a day.
Edit 2: Here is the thread where fat loss agents are ranked:
http://www.elitefitness.com/forum/showthread.php?t=64704&highlight=clenbuterol
The most popular fat loss agent nowadays has to be Albuterol, sort of Clenbuterol's brother, with less side effects. A good article can be found here:
http://www.elitefitness.com/forum/showthread.php?t=516463. Albuterol is a little more expansive because it is rarer and is more popular under a liquid form.
Suggested dosage is starting at around 4mg/day and ramping up to 4-8mg x3 a day.
I am unaware as to how long a cycle should last, probably like clen 2 weeks off 2 weeks on.
Then there is the infamous Clenbuterol, which usually comes in capsules (20mcg per) or also in liquid form. You start slowly at 20mcg a day and ramp up up to 120mcg (or higher if its not the first cycle). It is known to make you sweat and shake a lot, and is not to be taken before a work out. A good article is stickied on this board I believe. I tried it and my first cycle gave me very poor results unfortunately... doesnt work for all. Because the body adapts quickly it is best to run it 2 weeks on and 2 weeks off.
Edit 1: Here is an epic thread about a T3/Clen cycle (
http://www.elitefitness.com/forum/showthread.php?t=453769&highlight=clenbuterol) and a Clen FAQ (
http://www.elitefitness.com/forum/showthread.php?t=210446&highlight=clenbuterol)
There is also ECA (Ephredrine, Caffeine, Aspirin) wich can be home made (cheaper and better according to many) or commercial stacks. It's basically 25mg of Ephedrine, 200mg of Caffeine and 325mg of Apisirin taken together after a meal. You start at 1x per day, and ramp up to 3x per day. It is usually ran in conjunction with a Clen/Albuterol cycle (during the 2 weeks off). A thread about ECA:
http://www.elitefitness.com/forum/showthread.php?t=517246&highlight=clenbuterol
Finally there is T3, which can be stacked with both the ECA/Clen cycle. A cycle usually last 40-45 days. Cytomel (capsules @ 25mcg) seems to be the most popular product. It can also be purchased in liquid form. T3 is naturally being produced by your thyroid at around 25mcg per day, so going at higher than 50mcg for your first cycle is discouraged. Misusing it can disrupt your thyroid functions indefinitely, leaving you on thyroid meds for the rest of your life. When used correctly, it greatly enhances the effect of the fat loss.
There is also T4, which is just like T3 but seems to have a lesser potent effect and can be taken at slightly higher dosage for less risks. T4 is produced by your thyroid (specifically the pituitary gland) and then converted into T3 in the targeted organs. The conversion process is responsible for T4 being safer as its effect isn't direct.
Edit 3: There is also Thermorexin used in conjunction with T3 and Sesapure/Glycorell which seems to be giving amazing results to many around here but I know very little myself and the search function seems to be giving me the finger at the moment... Ulter could help you out a lot here as he seems to know quite a lot about it. Id be interested in knowing too

I just ordered some from the AF Store, will let you know if it worked better than Clen and ECA for me... a thread I found here:
http://www.elitefitness.com/forum/showthread.php?t=236148&highlight=THERMOREXIN+cycle
That's about as much as I can remember about it all. Remember all the above is true only with good cardio and a diet in check, but that seems to be the case for you already. I suggest signing up for Platinum so you can use the search function, if even for the first month, there is a ton of good information around here.
Don't be afraid to ask questions. Some idiots will shoot you down, but most of the people around here are helpful if you ask nicely and politely. Do your homework well before taking any of the above, as ANY drug usage can be very harmful if not used correctly...
Good luck !
PS. Oh and before taking everything I said for granted wait until somebody else reads it and clears it, just to make sure...