Where can I find the items I have bid on?

You can monitor the bidding status of an item in one convenient place. Auction Watch page Item Watch.
If you place a bid the item will automatically be added to your Personal bid page.

An email notification is sent when someone OUTBID you or PLACES a bid on an item.

If you prefer not to receive email notification of bid activity you have to uncheck the "E-mail notification & newsletter" in "Client Center".