Nails..., yes you can clip them, but not all dragons like it very much and you have to be very careful of the quik (like birds nails)

Another option would be to provide something natural that will allow the dragon to wear down the nails naturally...you can use rocks in the enclosure, or cement blocks/bricks, you could staple a piece of sand paper to the  the dragons favorite digging spot, you can also use a dremmel (a hand held electric tool used for grinding) vets sometimes use them for dogs that don't like getting their nails clipped...I personally use natural things to help...rocks mostly...

If you decide to clip the nails make sure you are very careful...if you clip too much and hit the quik, then the dragon may bleed, and could bleed a lot!  Make sure you've got some quik-stop (bird product) or some cornstarch (more cost effective, basically same thing), next to you just in case.