Question: I am currently working on my first website. I have no idea where to start on the CSS page, or if there are any standards that I should be following.

I would appreciate any links or first-hand advise.

Answer: 
You can save yourself a lot of headache by **understanding specificity**. When you set a rule for something, if there is a conflicting rule, **specificity decides which rule wins**.

A quick (incomplete) rundown: 

An element-wide rule (like `p {color:green;}`) will be trumped by:  

A class-specific rule (like `p.sidenote {color: blue;}`), which will be trumped by:  

An id-specific rule (like `p#final {color: red;}`), which will be trumped by:  

An inline declaration (like `<p style="color: orange;">`), which will be trumped by:  

An important rule (like `p#final {color: inherit !important;}`)

...all of which can be trumped by the user's rules.

The interactions can be complex, but there are mathematic rules underlying them. For a more complete treatment, see Chapter 3 of Eric Meyer's "CSS: The Definitive Guide."

To recap: **if you set a rule and it doesn't seem to affect anything, you've probably got a conflicting rule.** To understand why one rule beats the other, learn about specificity.
I have been building websites for 5 years now and still learn a lot by reading this every so often: <http://code.google.com/speed/page-speed/docs/rendering.html>

Also check out <http://www.zeldman.com> blog on CSS. This guy is a legend in the web world.