I am also trying to find out how to build my own forum from scratch. I know it is easier to go and download one, but if you are anything like me, I need to know the code behind them that makes them work. I have found that FrontPage is a good starting point, because you can see the code that is behind building the forum. Be aware though if you use FrontPage, you need to publish the forum before you can test it.

I hope this helps as a starting point.

With regards to WebHosting, I have used my ISP for the moment. A good site to look at for ideas of webhosting is 100bestfree-web-space.com. This identifies web hosts as either free or paid, which includes the low-budget, low-cost, pricey and high-end hosts. If you aren’t sure which price range of hosts you will need, start with one of the top 3 recommended hosts, which are low-cost web hosts. If you decide you need more attention switch to a pricier host, and if you need less features and support go for the free hosts.