How much to charge for web work?

I am a beginner freelancer contemplating the dilemma of how much to charge for web design work. Hoping someone out there can give a push in the right direction.

I know there are posts about this issue on this forum already. I've been looking at http://www.talkfreelance.com/showthread.php?t=13899 and http://www.talkfreelance.com/showthread.php?t=75653 as well as some pages on other websites.

Three things I have fortunately realized right away -

1. It's important to know exactly what the clients needs (at least initially). For example, a client might come to me and say 'I just need a website with 5 pages and a logo' but thats not enough info. I would also need to know if they require special functionality like a contact form, if they want anything dynamic on the site, etc. Only by knowing what the client needs (initially) pricing can be determined objectively.


2. Some clients will be charged hourly and some per project. I need to figure out when to do to which.


3. Watching out and reacting to "scope creep"

which for those who don't know basically means when into the project the client suddenly requests more than what was agreed upon initially. The client needs to be informed that hey, if I'm going to do more work than we initially agreed upon I will have to charge you a little more. Plus there should be a separate form for them to fill out indicating the additional work they want in detail.

What I'm trying to figure out is how much to charge for services (a-la-carte as well as package deals). For example, if someone wants a basic corporate site with no dynamic functionality, just a 5 page site with a contact form. How do you determine how much to charge for that? Also, how do you determine your hourly rate?