my new seeds :-)

Hey everyone,
Just got my 2 packs of cactus seeds-50 per pack. I want to have a nice garden, but there is no way i can accomodate even half of them (once they get big).
Thinking of starting just a few each for now. Not sure how to get started here... can anyone help? I was thinking of starting the seeds in square plastic containers with drainage holes drilled. Clear plastic bag, or a shower cap over top _~ I Have flushed cubes this way, so i am guessing it will work to start the cacti. What do you think?

Well I think I'll use a plastic kitty tray with holes drilled for drainage. Will be "bottom watered" by sitting in a slightly larger tray containing water. Clear plastic over top, and "we good" _~ Thanks for the replies everyone