Water leaking out around tub faucet handles

My home was built in 2002. This is a Jacuzzi tub (if that matters) with cheapo Delta faucet. A year or so ago the cold water faucet handle started leaking. The water seeps out around the handle (see photo). It only leaks at a certain point- meaning if I keep the pressure very low, just turning it on a little bit, it doesn't leak. But the harder I turn it on the more water seeps out. The hot water faucet handle has now started to develop the same leak. I went as far as I could but I'm not sure what else to do. I have NO plumbing skills so if you offer advice please dumb it down for me :) I'm not even sure I'm using proper terminology... anyway, I took off the plastic little lid of the faucet (see photo) and this exposed a screw- I then unscrewed that and off came that clear acrylic faucet knob. Now I'm not sure what to do from here. I have a feeling it is just a worn washer but how do I get to it? You can also see from the photo that there is standing water there from last night's bath. Any help you can provide is greatly appreciated! Attachment 42450 (http://www.doityourself.com/forum/attachments/toilets-sinks-showers-dishwashers-tubs-garbage-disposals/42450-water-leaking-out-around-tub-faucet-handles-faucet1.jpg)Attachment 42451 (http://www.doityourself.com/forum/attachments/toilets-sinks-showers-dishwashers-tubs-garbage-disposals/42451-water-leaking-out-around-tub-faucet-handles-faucet2.jpg)Attachment 42452 (http://www.doityourself.com/forum/attachments/toilets-sinks-showers-dishwashers-tubs-garbage-disposals/42452-water-leaking-out-around-tub-faucet-handles-faucet3.jpg) Thank you!