What kind and how much meta info is optimum

[Licker4U]

I kinda asked this in another thread because it was on topic with what was said but figured this was the most correct place to ask. I use meta keywords, seperated by commas, and they usually are more phrases than actual keywords. Should I just use words instead of phrases? Is there a way to put phrases in a meta location? How many keywords are acceptable? I've seen some sites witn no meta keywords and some with mini dictionaries. How about an example of what is the most effective use of keywords.

I've got it, how about a meta turorial without all the technical mumbo jumbo. Just the meat without the gravy.

(OK, a little gravy would be nice)