Today's topic is how to format lists.
If your lead-in statement is a complete sentence, use a colon at the end to introduce your list.
On the other hand, if your lead-in statement is a sentence fragment, I recommend that you don't use a colon. Some style guides agree with me, but a few don’t (see notes 1 and 2, below). To me, it makes sense that if you wouldn’t put a colon between the introductory element and the list items if they were together in a sentence, you shouldn’t put one there just because it’s a vertical list.
After you've completed the introductory sentence, your next question will be whether to capitalize the first letter in the statements that come after your bullets, numbers, or letters.
If your list item is a complete sentence, capitalize the first letter. If your list item isn't a complete sentence, you can choose whether or not to capitalize the first letter—it's a style choice. The only thing that is important is to be consistent. I capitalize the first letter of everything in lists because it's easier to remember “capitalize everything” than it is to remember “capitalize complete sentences and use lowercase for sentence fragments.”
With capitalization covered, you're on to your items, and at the end of the first one you have to decide what kind of punctuation to use.
If your list items are complete sentences, or if at least one list item is a fragment that is immediately followed by a complete sentence, use normal terminal punctuation: a period, question mark, or exclamation point.