CYA is what is commonly called "stabilizer" or "conditioner" at the pool store and is one of the items you will need to buy from them (unless you have been using dichlor or trichlor (stablized chlorine), then it is possible that your levels are ok or even too high( means you have to run you FC at a higher level is all).
It helps keep the chlorine from degrading in sunlight in an outdoor pool. It's bad side is that the higher the level of CYA the higher you need to run your FC so your water stays sanitiezed and doesn't turn green! (It actually combines with the chlorine in the pool so it becomes less reactive as an oxidizer if I undestand it correctly) If you are not using a SWG most people run it around 30 -50 ppm. With a SWG most manufacturers recommend between 60-80 ppm. Before the big crash their used to be a table on here of what to run your FC and and what levels to shock for various levels of CYA. Perhaps one of these day Ben will get around to reposting it for those of us who never saved a copy

First thing you need to do is get a 5 way test kit that is drop based such as Ben's (best value for the money), Taylor K-2005 (good), K-2006 (Better but Ben's is still a better value for what you get), or even the $15 kit 5 way drop kit from Walmart (to hold you over until Ben's kit arrives in the mail!) (If you think I am pushing Ben's kit let me refer you to this thread

http://www.poolforum.com/pf2/showthread.php?t=151

and let me say that I have kept salt water aquariums for over 30 years now and have had quite a bit of experience with water testing using reagents, strips and electronic equipment--SO GET BEN"S KIT ALREADY! It's worth every penny!)
Second, post a full set of readings on here. These would be:
FC (free chlorine using the FAS-DPD titration test)
TC (total chlorine using the FAS-DPD titration test or the OTO test, first way is more accurate, second easier)
TA (total alkalinity)
CH (calcium hardness)
pH (what else?--pH)
CYA (and this is one of the places Ben's kit really shines--you get 10 oz of reagent. Taylor only give you 3/4 oz which is only good for about 5 tests)

Once you post your numbers you will find that the moderators and other friendly folk on here will be beating down the door to anwer you post and give you the guidance and encouragement you need to REALLY learn how to keep your pool clean, healthy and happy!