Go to LR2000 or contact your state BLM office (BLM handles all mineral claims for both BLM and USFS). Once you have found if the area you are interested in (by Township, Range, Section) has claims on it, plot them out and see if your spot is claimed (LR only breaks out to 1/4 section). Also check with the county recorder to see if anything is recorded that has not hit BLM yet. If not, prospect it and see what is there. If you come up with the yellow stuff, get a copy of the claim location notice at a local big book store.
If everything comes up clean, get a claim location notice form, fill it out, record at the county, and send with fees to the state BLM office. Make a couple of copies and post one on the claim, in a waterproof container, in plain sight. I use a piece of PVC pipe capped at one end and a screw cap on the other, paperwork in a ziplock bag (location notice and map), and some small steel cable and cable clamps to attach to a tree, with room for growth so the cable doesn't cut into the tree.. You have 60 days to record from date of location and 90 days to file with BLM.
BLM can send you a packet with all the fees and such if you request it. Right now I'd wait till after the first of Sept to file a new claim, as BLM goes by location date for collecting fees.....ie. - if you file now you would pay fees for this year, and unless you file small miner's exemption with it, you get hit again by Aug. 31st for next year.
Hope this helps, good luck.