Ok, first of all, slow down. Quality over quantity. One map at a time. We have hundreds of poorly made/rushed maps already. What we need is some well-designed, detailed, and thoroughly tested maps. Probably the best of the bunch there is the battlefield one, but it only has one path and absolutely no cover.
Take the time to design each area of your map. Consider where the bottlenecks will be and avoid having only one path to a particular location. Think of it this way: no matter where somebody is, there should always be a path around him so that you can sneak up and shoot him in the back.
Once you've designed and built your map, release it as a beta -- the typical naming format is mymap_b1.bsp. Post it on the forums and have some people test it. It's also a good idea to include the .map file. Listen to the feedback and make the changes people suggest, then release another beta, mymap_b2.bsp. Continue this until the testers feel it's complete, then rename the final beta map to mymap.bsp (mymap being whatever you want to call it -- and make it all lowercase so it's Linux friendly).