My cycling was finished in about 2 weeks because when I did the small water changes I added water from my uncle's cycled tank. If you can get gravel, decoration, water, etc. from a cycled tank, it will really speed up the process. Live plants also speed things up. Otherwise it takes about a month, I think.
You can split it up 3 ways, that's a little more than 3 gallons each. Fines for bettas. :)