The classic technique for vocal capture with zero budget is to put a duvet over your head while recording. Failing this, you can pin the duvet to the walls of a wardrobe or something and sit inside that. Failing that, you may wish to build a little fort out of cushions and blankets or something. You may wish to do this anyway.
The traditional pop filter made from a pair of tights and a wire coathanger works very well too.
Also get some good closed back headphones asap, so you can monitor how you're coming in as you speak.
The next thing to think about after you're getting a decent capture is some kind of dynamics control, ie. compression, but that's beyond the scope of this comment.
Good tips! For monitoring, I love the Beyerdynamic DT 100 headphones. Being closed-back, you can be acoustically separated from your recording space, allowing you to hear its acoustical characteristics (which is the reason why engineers in studios sit in separate spaces from the musicians). You’ll be able to hear the effects of your experiments with duvets :)
Like the parent says compression is also quite important. It’s a big part of what makes radio voices sound radio, for example. Seeing it simplistically it is basically about lowering the dynamics of your sound—make the loud parts softer, so you can make the whole thing louder.
Any audio editing software comes with basic compression plugins. It takes some exercise to get right. Also, as you are making parts of your recording louder, any bad acoustics, noises artefacts are amplified.
Some recording software allows you to monitor effects while you are recording—this can help in finding the right acoustics. Of course there will always be a slight delay—a dedicated hardware compressor solves this problem.
One more thing: you should definitely look at the Reaper recording software: http://reaper.fm/
It has honorable pricing, an unlimited trial, and every feature you could ever need. It's particularly well suited for the kind of stuff you're doing: it has ripple editing, automatic alignment of repeated takes and so on. Can't recommend it enough. Make sure to read the manual though, it uses the mouse buttons in an unusual way.
The traditional pop filter made from a pair of tights and a wire coathanger works very well too.
Also get some good closed back headphones asap, so you can monitor how you're coming in as you speak.
The next thing to think about after you're getting a decent capture is some kind of dynamics control, ie. compression, but that's beyond the scope of this comment.