Hi again Jenn
OK, I'll try and take some of this on....
1) Alexa traffic stats are not really very reliable as they measure only visits by users who have the Alexa toolbar installed. As the toolbar only used to be available for IE (although a FF version has recently been introduced) the actual visitor numbers for that site are almost certainly much higher. How much higher is anybody's guess. If you look on the Alexa site again you will see tabs that will allow you to view various periods of stats from a day to a year or even 5 years.
2) For your questions about CPU issues, 25% of one hosts shared server CPU load will be different to 25% of anothers. It's very difficult to know just how much shared server CPU will be available to you until you run into problems. Have a look at this thread on WHT for a little more insight into what it all means. Very busy forums can run into CPU load problems, particularly if the host crams a high number of users onto their shared servers, but this discussion will give you a feel for the sort of issues other forum owners have had or are having. You can always ask on those boards for some guidance and talk numbers, even if you're only really guessing at this point.
Looking for help choosing a host to move from current one - Web Hosting Talk - The largest, most influential web hosting community on the Internet
3) The WHT forums are also a good place to discuss things like server side processes but from what I know of your plans, it shouldn't concern you too much so I won't go into a long technical explanation. Just as an example, search engines use server side processing (ss is faster than client side processing). When a keyword is sent, a program on a server matches the word or phrase entered against an index of website content. To complete the same task as a client-side process would require the browser to download the entire search engine program and index. If you are at all concerned, make it another point to clarify with your eventual choice of host, but it doesn't mean unmoderated forums
4) How much disk space will you need? Probably far less than a decent host is going to provide. As a very rough guide, it is fair to say that most users will need less than 100mb and others would be hard pressed to use more than 1-2 Gb. (My last complete backup of the TCH domain was around 20mb) As I say this is rough but unless you are hosting huge video/image/sound files space shouldn't be too much of an issue.
5) CPU usage and bandwidth are separate issues. Bandwidth refers to the total amount of data transfer allowed per month. I have no idea about how much would be enough but maybe ask some forum owners about their traffic and how it translates into bandwidth to give you a feel for numbers? In simplistic terms, more traffic means more bandwidth, so as your site grows you will use more and more. You can monitor bandwidth use via your hosting control panel so if you start approaching limits you can always take action to ensure you don't exceed them. (Wise, because there are some hosts who will slap you with a bill for going over your monthly bandwidth allowance).
6) SMF bulletin board software is one of two provided by my host via Fantastico. The other being phpBB2. SMF have their own forum at
Simple Machines Community Forum - Index
7) I have no direct experience of either of the hosting companies you mention I'm afraid and can only say that BlueHost are popular, have grown rapidly, and are the host of choice for a lot of bloggers. Would they suit your needs? I can't really say, sorry. Perhaps once again, not wishing to sound like a broken record, seeking out some forum owners and learning from their experiences would be best possible advice. I've never run a forum ;-)
8) To better understand all the "unlimited" this that and the other, there is an article on my blog which attempts to explain in simple terms what "overselling" actually means, hopefully without too much jargon.
Web Hosts Overselling | The Cayman Host
Unlimited bandwidth is not an automatic red flag, just look for the real limits which can usually be found if you delve a little deeper into a hosting company's site, once you have some idea of what you're looking for.
I hope this helps you a little further along - I'm sure it is intimidating, but it sounds as though you are determined, so good luck in your ventures.
Mo (TheCaymanHost)