1. What are the requirements?

The first thing you should check are the requirements for the script. If your hosting can't run it, then don't bother looking any further, yo'ure just teasing yourself.

2. What features does it have?

Does this script have all the features you want? If not, how many is it missing? Will you be happy if you install it, or will you end up needing to change to something else in the end? If you're not going to be satisfied with it, then don't waste your time!

. Is this customizable?

You or your designer probably have an idea of how you want your website to look, so make sure this script will conform to that in some way. Perhaps it let's you change colors, or graphics? Perhaps it has a flexible layout? It will look better and you'll be much happier if you can find something that will fit seamlessly into your site.

4. How hard is this to install?

Some scripts are very easy to install. Just upload the files, answer a few questions through your browser, and you're up and running. Other scripts are more complicated, and require you to get right into the code to set it up. Depending on your PHP skills, you may prefer one style over the other. Take a look at the "read me" file first so you know what you're getting into.

5. Does it offer support?

A lot of free scripts and even some paid ones come 'as is'. If you are having trouble getting it to work, you may not have anyone to ask for help. Sometimes you can get support directly from the author or from an online community of fellow users. Although a majority of the time things go smoothly and you never need it, its still nice to know support is there.

6. Is this modifiable?

Some more popular scripts (phpBB and wordpress come to mind) have tons of 'mods' or 'plugins' written by other users that you can download to add new features to the original scripts. If a script doesn't do exactly what you want, perhaps you can find a mod for it that will. Mods can be a great way to expand features on a good script.

7. How much does it cost?

Cost is a big issue for many small inteet startups or personal websites, so you have to keep it in mind before choosing a script. They say 'you get what you pay for' and sometimes that is true, but often you can find very good scripts for little to no cost. Just be patient enough to sort through a lot of options, and you'll find something in your budget to do the job.