get some cheap azz Chinese end mills off amazon or ebay, play around with them for a while, struggle to get good cuts, then once you get all the kinks out of your system buy a few decent new endmills of Amazon (you can get HSS or Cobalt for $5-8 if you're patient and aren't too picky) and marvel at how much better they cut. I used to buy endmills off ebay, but unless they're new it's a crapshoot about how worn they are. A dull endmill will cause you no end of frustration and it's not like you can sharpen them easily yourself.
Over the last couple of years I've built up a very nice set of new long, short, 2, 3 (prefered), 4 flute, finishing, roughing and ball end mills from 1/16 to 1" for probably about $250. I think the most I paid was $10 for a 1" 2 flute to use as a mini face mill.