You either code them with XHTML or you good on some site like godaddy or something for a template forum site. Hope this helped.

Here's a list of the best free ones and paid ones.

Free Downloads
mybb
phpbb

Paid
Xenforo
VBulliten
IPB

If you want to create the forums yourself then you should look into PHP (the server-side scripting language) and MySQL (to work with a database). Good link to get started: [ Register or Signin to view external links. ]

Creating good and secure forums will be a big task, and pretty much impossible if you are unfamiliar with PHP/MySQL, so you might want to get some experience with PHP/MySQL first. If you decide not to do it yourself, then look into the links posted by Cgallagher21 above.

If you want to make an interactive website you will need to use PHP and mySQL, you can use dreamweaver for this if you aren't experience writing code for PHP

Creating a simple forum board is not a tough task. Just a time consuming project.

However, creating a forum board like MyBB will take months even years if you are doing it by yourself and the main reason is because there are TONS of stuff you need to code.

here is just a brief list:
Admin CP - Which is a separate site (tech)
Mod CP
User CP
Member's Page
Categories
Forums
Threads
Replies
Permissions per group
Etc...

But here's how to do it:
1) Write out (on paper) all the features that you want

2) Use Pseudocode to make your structure (You want to use classes)

3) Start from your "LOGIN" page, then expand. Here's how i will do it (although it might be wrong)

A. login / logout script ->
B. registration script >
C. Member's Page >
D. Member's EDIT page (or user cp) >
E.Categories
F. Forum >
G. Threads >
H. Replies >
I. Permission PER Group. So ADMIN can edit all post, etc...
J. ADMIN CP

Etc... It's a long process.

Some hosts supply a automatic install of forums. You'll find it somewhere in the cPanel.

Basically.

You want to buy hosting from somewhere. I recommend "EdenHost". It's very cheap and reliable. GoDaddy hosting and Hostgator are overpriced.

In cPannel go to something called "Softaculous" and choose MyBB or some soft of forum softwere. Once you go through setup you have a forum. Feel free to customize.