Integrating WordPress into existing template

I just found out about WordPress and it seems pretty cool, I just have one concern about it. I didn’t come across an answer for it, you’ll have to excuse the total “n00b”iness of the question.

I have a website I’m working on and have set aside a section on it for my blog. I have a page for blogs to appear that is consistent with other pages on the site – with a specified Sidebar area and a main content area.

Can I install a WordPress blog onto my site that conforms to the existing template I have in mind? Will it seamlessly write into the existing main content area I have, and have blog navigation (archives/past entries and such) in the sidebar?

Also, is this difficult to do?
I’m pretty good with XHTML and CSS, but am still a beginner when it comes to PHP.

Thanks.