When there is no sentence, phrase or anything before the list, then obviously no punctuation is required.

Example:

You can fill the basket with diapers, baby wipes, baby lotion baby powder, baby oil, and NS bottles.

If there is a phrase or sentence fragment (weak clause) before the list, then use a comma.

Example:

Remember that, you can fill the basket with diapers, baby wipes, baby lotion baby powder, baby oil, and NS bottles.

If there is a sentence before the list, which is a complete sentence (strong clause), then use a semicolon after the sentence and before the list. The semicolon must have an introductory phrase (For example [e.g.], that is [i.e.], or for instance) after it and a comma must come after the introductory phrase.

Example:

You can fill the basket with Baby Products; for instance, diapers, baby wipes, baby lotion baby powder, baby oil, and NS bottles.

Use a colon when you do not want to use an introductory phrase; in this case, you would use a colon instead of the semicolon.

Example:

You can fill the basket with Baby Products: diapers, baby wipes, baby lotion baby powder, baby oil, and NS bottles.

Go to this website: www.grammarbook.com

That is how I learned grammar; you'll love it. =D