SpeedyFinger is the only penny auction site to offer free bids to beginners. There are free auctions that appear during the day, so you can win 5 free bids easily. One user has amassed over 200 bids for free and used them to win the reserve auctions easily. SpeedyFinger works differently from traditional PA sites, as most of their auctions are reserved.
The owner is trying out timer auctions to see if anybody wants to bid on them. The owner's business model seems to work quite well compared to other PA sites that shut down recently. You can join in too and see if you get the chance to win free bids and hope to hit the reserve to win that gift card. The $10 Amazon e-gift card auctions are the easiest to obtain. As for free bids, be prepared to do some furious clicking and hope to win 5 bids easily. I did and got myself a $10 Amazon e-gift card easily.