DMARDs stand for Disease modifying antirheumatic drugs. The following are a list of the ones I've taken and a brief description of my experiences with each one.
There are two types of drugs I've always been on: one to control my arthritis (like a DMARD or biologic) and one to control daily pain and inflammation (NSAIDs).
Methotrexate usually is a chemotherapy drug, but in small doses can be used to treat juvenile rheumatoid arthritis and rheumatoid arthritis. As far as I understand it, it works by slowing the reproduction of cells that reproduce at a fast rate. I'm not sure how this helps JRA, but it certainly worked in my case. I was on methotrexate for about 10 years. I took it orally at 25 mg once a week for about 7 years. Eventually, I had to start taking it subcutaneously because 25 mg per week is the highest recommended oral dosage. The shots were okay at first. It stung and would temporarily stain the skin at the injection site yellow, but it worked and was controlling my JRA. That was the most important part for me. It also dried out my skin and thinned my hair. No one else noticed that my hair was thinner than it could have been, but I noticed a huge difference in my skin and hair after I stopped taking methotrexate. Methotrexate also can be used as an abortant (i.e., if you're pregnant, it can kill your baby or severely deform it), so getting pregnant while on methotrexate is just not an option at all.
I ended up stopping taking methotrexate in April of 2002 because I suddenly developed a very bad allergy to it. My liver also was starting to be affected by the methotrexate; my liver blood test results were way off: the enzymes were about 3 times higher than they should have been. I was covered in hives for about two months before I stopped taking methotrexate. Since then, I haven't seen a single hive. Methotrexate also has some potentially very scary side effects. I will list some links for more information about methotrexate later.
I was on plaquenil for about 2 years. I didn't notice much of a difference at all and stopped taking it when I began seeing spots in my field of vision. (Plaquenil can cause eye problems.)
Arava works in just about the same way that methotrexate does. I was only on arava for a few months, though, because it upset my stomach very badly. It was controlling my jra, though, but I couldn't deal with my stomach hurting so much. It would hurt after every meal, no matter what or how much or how little I ate.