Odds are it's the fork seals leaking, very normal on dirt bikes. The common cause is accumulation of small dirt particles in the seals. If it's the first time my seals are leaking, I usually just take the forks apart and clean everything, and replace the oil. If they start leaking a second time, I replace them. It's a job that seems very intimidating the first time you try it, but once you try it, the next time will be a breeze (well, sort of). My best advice is to buy a shop manual for your bike. Will be the best investment you make for the bike if you plan on keeping it awhile. There's a couple of special tools needed for the job that can be easily made yourself for a fraction of the cost of the fancy tools.
To prolong the life of your seals, try
SealSavers. I can honestly say that I've never had a fork seal leak when using them, and that's probably pushing 5 years now. I do take the garden hose and spray on the inside of the SealSavers to get the dirt out of them after each ride, but other than that, they're maintenance free and the best thing going.
If you do decide to tackle the fork seal job yourself, you'll always have plenty of help here. Good luck.