Just got of Grandeur of the Seas two weeks ago, so I am freshly versed in tipping for RCI. As Kuki mentioned, a Tipping Form will be delivered to your room early in your cruise. If you choose to use this form and have the tips added to your Sea Pass Account, be SURE to pay attention to the Deadline for this form. My husband and I were on a 7 day cruise ending on a Saturday, so tip night was Friday...the form had to be in by midnight Thursday and we forgot. The Purser's Desk really couldn't explain why we still could not charge to our Sea Pass when everything else on the ship can be charged up to the minute you walk off, but that is RCI policy. Luckily, we had enough spending money left to appropraitely tip everyone.
I would recommend using the vouchers though just in case you do run out of spending money...otherwise, you have to use the ship's ATM or not tip at all. If you fill out the form, the vouchers are delivered to your stateroom which you place in the envelopes that are also provided to you. You can add additional cash at that time too if you feel that person deserves a bigger tip. You then hand the envelope to each person on tip night.
Those that should be tipped include your Cabin Steward, Dinning Room Head Waiter, Table Head Waiter, and Table Assistant Waiter. Your two waiters at your table handle everything at your table all week from ordering to clearing. The Dinning Room Head Waiter really only just oversees them and will check on your table throughout the week. We left our envelope for our Cabin Steward in our room with a note on the final night, and handed the envelopes to the wait staff in the dining room on the final night at the end of dinner. I asked our table head waiter to pass along the envelope to the dinning room head waiter since he was not around. It is a little akward, but it is part of the drill, and everyone else is doing it too.
Those are the only folks that should be tipped. The head table waiters cover the dining room during the other parts of the day, and the assistant table waiters are usually covering the Windjammer, so everyone gets tipped. Gratutity is included in all bar drinks, so they get tipped. And apparently the Cruise Directing Staff are paid well enough that they are not expected to be tipped.
This was our first cruise too, and we loved it...HAVE A GREAT TIME!