Hey, check out the link to my site for pics of my tanks. I have been keeping bettas for years, so here are the basics i can name off the top of my head.

Ok you need to clean the tank once every one or two weeks. (depending on homw dirty the tank is.)

they do not need much water, as they originated from asia and live in small puddles of water.

1-2 litres each tank, or in each section is sufficient. Some bettas will die if put in a bigger tank as they are not use to it, and the water takes longer to heat up because of the surface area to volume ratio. if you are going to put them in a bigger tank, make sure to have a heater and plenty of plants (real or fake) to hide behind. You do not need a heater for a smaller tank, but plants can still look good if you can fit it in.

I am guessing you realise they should not be in contact with each other, so i wont bother going into that.

If you dont want to clean out their tanks as often, you could get a filter, it is up to you. it also depends on the size of the tank.

Males can be kept in cold water or tropical, while females should only be kept in tropical temps.

I would recommend getting a number of small tanks, or one like mine that is specically made for bettas, and sectioned off. (see my website) then you dont have to worry about heaters or filters etc.

You can you pebbles or gravel or glass stones etc, just make sure that it is safe for the fish, and has no residue on it. and no matter where you get the stones etc wash them again yourself.

I find cleaning my tanks quite easy. just get a small net and place the fish in a small cup of water while cleaning the tank. (You dont need the net if you just want to catch it with the cup, but they are fast little swimmers when they want to be. Then just wash any ornaments with an toothbrush (Just buy a cheap one) and tip the stones into a sieve and run water over in while shaking it around. give the tank a wipe. Never use cleaning products, or anything that is used for cleaning, eg dish washing brushes, as the residue from the chemicals could harm them. if you need something for stubborn dirt or grime, use brown vinegar, or white if you cant get a hold of brown and wash it out thoroughly. Then just put everything back in and add some of the water conditioner. NOT CRYSTALS. go for something like this.

www.aquariumpharm.com

umm.. i hope that helps, if you have any more questions just ask. oh and dont forget to sign my guestbook when you visit my site.