Face it, juggling studies, homework and your "job" would be very stressful, it'll take a toll on you soon enough. After all, you'll be expected to produce what a full-time worker does in a 8 hour day- and clients can be VERY demanding.

Very nice design, but let me comment a few things on your (x)html usage.

1) Doctype
DO NOT use transitional. Always use strict, by using transitional you put the browser renderer into quirks mode. This means it tries to fix things for you and ignore the standard way of doing things. This in turn will make it harder to find any possible errors or bugs.

Read this: http://www.quirksmode.org/css/quirksmode.html

2) Understand the tags
The paragraph text is meant for paragraphs and thus text. Paragraphs do not include lists. Those should be placed outside the paragraph. Each tag has a meaning, so use it accordingly.

3) Learn the purpose of attributes
IDs as you know are short for identifiers or identities if you will. Which by definition is unique. You must not have 2 IDs with the same value, regardless of the tag. Also the anchor tag does not have an "alt" attribute. You should also enter some text in the "alt" attribute for your images. A short description of the image would suffice.

HTML Reference: http://www.w3schools.com/tags/default.asp

Besides that, you are on the right track dude. Keep up the good work