Chances are that I will probably get some thing wrong but any way.

I am new here and the holidays are coming up soon and I thought that I might try my hand at making games.
I already have an an idea:

Basically a city building game.
You start with X amount of buildings in a small land space where only you can build. To gather resources you must play these little mini games to determine the rate they come in as well as assign more people towards it. Buildings will probably be build in assigned spaces. With you only being able to build X amount of builds which are upgradable to provide extra uses and effency.

The objective is generally going to be to beat (Either through military or other means) your opponent. Side note; this will NOT be an RTS for the console.

Am I missing anything?
Questions and advice are appreciated.

Any advice will depend on your programming background, so, what is your programming background ? :)

As a general advice, I'd say to not try to elaborate some potentially complex gameplay at first. Try to prototype some part of something you would like to do, without having a clear idea of it so you will see what are your capabilities and how far you can go. Then, start thinking about a gameplay considering your limit (or start learning seriously if you think you'll be able to go further than your current skill).

Ho, and welcome.

And while we've got your attention here, definitely take the time to read the "Help! I'm new!" FAQ since it's advice will help get you going in the right direction based on your skill level (also a good idea just to read through all the other FAQs briefly just to get a feel for the community and what it has to offer).

I have some experience in CSS and HTML.
I am a novice overall so in hear what I have been told I'll stick to something simple.
Thanks.

Knowing what your capable of is definitely the first step in making a game.
You have to ether be a good artist and have a programming friend, (vise versa)
you really have to question yourself on this, and if your not a very good artist or a programmer, well, now is the time to learn.

James Speed Kerr:

I have some experience in CSS and HTML.
I am a novice overall so in hear what I have been told I'll stick to something simple.
Thanks.

You should really go for a C# course first(buying a C# book may be very useful). HTML isn't a programming language, so it won't really help you.