With a short series (list), use commas. However, do not use a comma before the final conjunction.
With a long or complex series (list), use semi-colons.
Note that at the end of a series of semicolons, “and” or “or” may be omitted, however the final series semicolon cannot be omitted.
(See the Commas section.)
For more information on punctuation, see the CP Stylebook.