I live in Reston (moved here about 5 years ago), and the local lakes are a pretty decent place to scratch your fishing itch when you can't make out out to a larger body of water.
No one really helped me much, so I had to figure out the area by trial-and-error over the last few years... here's what I've learned:
Lake Audubon probably has the best variety, IMHO, if you have a canoe or small plastic boat. The boat docks usually produce some decent largemouth, and there are some good sized catfish and carp in there as well. Bank fishing is tough, except for the area near the dam (which can be pretty decent in the pre-spawn when the sun warms up the shallows.) Lake Anne also has some decent fish, but they're pretty wary given the pressure they've seen... again, shore options are limited. Your best bet is to spend $200 on a cheap eBay canoe if you want to fish either of those (or most of the places I'm about to mention below, as well.) My little boy and I love going to either one, and when it slows down he can pull out palm-sized bluegill all day on pieces of nightcrawlers in either lake.
Best fishing -- bar none -- within 5 miles of Reston is the Upper Potomac for Smallies, though. For shore fishing, the area about 1-1.5 miles up-river from Riverbend Park (hike along the trail until you get to the good riffles about 1.5 miles from the main park parking.) I've pulled out 3 and 4 lb smallies from the pools there from spring until fall -- but you DO have to wade. The shore doesn't really work. The other side (the pools near the islands, not all the way to the Maryland bank) is actually a lot more productive, and if you have a canoe, in addition to smallies, you can get some good largemouth action in a couple of the backwater areas and along bank cutbacks as well.
Burke and Occoquan are a bit of a haul, and neither can really be fished without a boat -- but again, a canoe is all you need. Both are tough, but probably have the largest largemouth around NOVA, other than in the lower Potomac.
Bank fishing is also decent at the ponds at Claude Moore park in Sterling. Both have decent numbers, but small size, as both are stocked with largemouth, bluegill and catfish every year. Just don't go on a weekend, since it's a zoo of kids with their SpongeBob rods learning to fish. I've caught as many as 15 largemouth in 2 hours there one spring afternoon during the week, but none were over 2 lbs. I've also been skunked if it's right after a heavy weekend.
For ALL of these spots, I've found the best baits are 5" Senkos in green or pumpkin, and floating Rapala's. I've tried everything in my box over the last couple of years, but these 2 lures are constant producers for me. You can also use twist tail grubs when in the Upper Potomac for Smallies, but I actually prefer the Senko's there, too, since they tend to catch fewer, but larger, fish. If you've never hooked into a 4 lb river smallmouth, you just haven't fished! NOTHING fights like good sized river smallie -- they are pure muscle from fighting the current all day. Even the dinks are a good time, especially on a medium-light spinning rig.
Beaverdam is TOUGH to fish... and bank fishing is tick-central. Do NOT even try to bank fish there unless you are covered in DEET and wearing permethrin-treated pants. The place is crawling with ticks. If you have the above-mentioned canoe, then you can get to some good spots on Beaverdam, but I've never been able to figure out a pattern there... it's hit or miss. I guess traditional spinnerbaits (white or chartreause) are probably what I've caught the most fish with on Beaverdam, and that's usually trolling behind the canoe when moving from spot-to-spot, or on long casts off of the points.
There... that's the last 3 years of Reston-area fishing summed up in one post.