New to WP – very basic question

I design websites for people in my “spare time”, so far all small, more or less single purpose sites for a small business to get a web presence. The only tool I have used from time to time is NVU, and for my first site I used Mozilla’s web authoring. The last few sites I have done were mostly just done with textpad and a couple of generic CSS files I use to build div boxes for content, some free javascript and some very basic PHP for menu content that can be edited in one place. I am not a programmer and have never taken any formal programming training, other than Oracle PL/SQL as my day job is a database admin.

However some of my customers have been asking for more enhancements, like online reservations, live feedback, etc.. I have considered using something like Joomla (I’m not even 100% sure what it does) or something similar, when someone told me that wordpress will do everything I need and more. Having a quick look at it I get the impression it is more or less blogging software to build an online blog, but I’ve heard it can be used for any type of website.

So, my questions:

First, can I build any type of site with it?

Do my hosting services need to support it?

Can I build on my existing code (sites) with it?

Where is a good place to start? (any tutorials I have seen are for building personal blogs, not what I want to do)

thanks!