There are no charges to bid. Charges are only incurred if you are the winning bidder. Some auctions may be subject to a buyer's premium charge, which will be outlined in the terms & conditions of the auction.
Click on My Items in the top right of every bidding page. That will bring up a list of the items you've placed bids on. Each item will list the time left in the auction, the current bid, your maximum bid and the status of the auction.
You may increase your maximum bid at any time before the auction has ended. If you decide to increase your bid while you are still the high bidder, the current bid will not increase (you will not be bidding against yourself).
Remember to refresh often to be sure the bids on display are the most recent. Either use the refresh button next to each item in the catalog view or use the refresh button in your browser.
To place a bid, you must be registered and approved for the auction. See how to register for an auction.
Once a bid has been placed, there is absolutely no way to cancel it under any circumstances.
"Forced Bid" is a bidding strategy by which a bidder increases the bid by more than the next accepted bid (placing your bid at $150 when the next accepted bid is $125). This practice is used by some bidders to discourage others from bidding in hopes of acquiring an item at a lower price. There are many theories on the effectiveness of this practice and a bidder who wishes to apply it does so at their own discretion. The auction company will not lower the price of an item that has been won by a "forced" bid with no other competing bids.