Any that don't respond by the end of the business day should be dropped from your list immediately. Autoresponders do not count. Any host that just sends a price list and does not respond with actual answers should also be dropped from consideration. Double-check that the hosts you're researching will allow you the access you need to install and run your forum software. Some providers advertise telnet access but actually offer a control-panel program that doesn't allow access to the command line like a real shell account does.
Most web conferencing software installations require access to the command line.
In addition, command line access is useful for figuring out why the script you just installed won't run when you access it with your browser. You can run it from the command line to see if doing so generates any helpful error messages. Find out what kind of hardware your site will be hosted on. 200mhz Pentiums on T-1 lines are a thing of the past, and indicate that the provider is not upgrading hardware frequently enough. Pentium IIs, 400mhz or better on multiple T3 or OC3 lines will probably deliver pages to visitors faster, although an overcrowded server will slow down delivery.