If your students are anything like mine, they overuse parentheses (where they learned this, I have no idea!) and they view semi-colons to be as about as foreign as hieroglyphics. Although punctuation needs continual revision, reinforcement, and practice throughout the year,  I have included a PowerPoint that I use to bring everyone to a baseline of rules for the four common punctuation marks needed to expand sentences concisely and coherently.

If students are unfamiliar with independent and dependent clauses, or compound and complex sentences, I have uploaded another PowerPoint to introduce these grammar concepts.

A great place to find free, printable worksheets is:

http://www.k12reader.com/subject/grammar/punctuation/semicolon/