Too many Commas

I have a huge problem of over using commas. I never know when to use, and I also never know when not to use them, so I found some rules of when not to use them. I hope they help.

1. Don't use a comm to separate the subject from the verb.
2.Don't put a comma between the two verbs or verb phrases in a compound predicate.
Don't put a comma between the two nouns, noun phrases, or noun clauses in a compound subject or compound object.
3.Don't put a comma after the main clause when a dependent (subordinate) clause follows it (except for cases of extreme contrast).

These rules, and also some examples can be found at the following address

http://owl.english.purdue.edu/handouts/grammar/g_comma.html