I'm working on a promotional piece involving a giveaway and don't know the promotional laws involve with giveaways.

If you are just giving something legal away for free I do not believe there are any laws against giving items/services away. At least in the online market place there are many websites that offer some free incentive for sigining up for a news letter or for contacting the company. IF however you are running a sweepstakes then there are a lot of different rules. Look to the federal and state laws to find out more.

Here is a start:
Sweepstakes - Wikipedia, the free encyclopedia