*resort fees. The first time we stayed at the Paradise Pier, the front desk clerk didn't say one word about the resort fee ($7/day, I think), and there it was on the statement they slid under the door on checkout. When I called the front desk to gripe the clerk said it was for coffee, newspaper, self parking and the fitness center. OK, but they only give you the USA today on weekday mornings, and the 2 mornings we were there were Sat & Sunday and no paper was delivered to our room; we don't drink coffee; we would have used the fitness center had we know we were paying for it anyway (but didn't because we thought it cost extra) and we were valet parking our car at $12/day! They took it off the bill. I would have paid it, had the front desk clerk who checked us in told us about it, particularly that it included use of the fitness center.
*parking. ALWAYS ASK if there is a charge for parking, even for self parking. All Disney properties charge for parking, and the bigger hotels such as the Anaheim Hilton also charge.
*tax. Room tax in Anaheim is 15%. In Garden Grove it's 13% and in Orange it's 10%. Depending on where your hotel is can make a difference in your total hotel bill. Ask when you make your reservation.
*energy surcharges - I haven't seen one since the summer of 01, but when they were around they were $3/day.
Hope this helps!!