Hi, bingymon! You asked:
"What about repeating the same word like "keyword" & "keywords" or "meta keywords". Would it work just as well to use "meta, keywords"?"
It's not 100% clear what you mean by that, but you will only want to do ONE keywords meta tag, which is not of prime importance anyway, since it's the page text you need to have your keywords in.
You'll need the title, meta description tag, and meta keyword tag, one of each. Here are some basic articles for you to read:
The ones under "Design and Development" and "Meta Tags" might be where you'd best start for a good foundation. You'll probably want to choose a few of the best keyword phrases and use them across the site, and concentrate on specifics for given pages.
What Mr. Mackin said:
"You may use about 1024 characters BUT you may want to focus the theme of your page and use MUCH less."
That's what to do.