That's certainly the best option.
The doors open at 9 o'clock, and you go to the desk, pay your £15 and they allocate you a desk with a terminal which is yours for the day. The staff will help you to become familiar with the system, and they will also help if you run into a problem during the day, for example something you can't read. You can look at more or less anything you like that is on the system.
You can print off or save to a memory stick (at extra charge - you need to put money in your account up front) any birth certificate up to 1914, marriage certificates to 1939 and death certificates to 1964. You can look at later ones, and make notes, but you can't print or save those.
So all you need to take is a list of your starter questions, and some means of recording and making notes. I use a notepad computer with a genealogy program but lots of people use a pencil and paper.
You don't even need to go far for a lunch break. There's a cafe just across the garden in New Register House, barely far enough to get wet when it's raining.
They ring a bell 15 minutes before closing time, and again 5 minutes before closing, and the system will shut you out at 4.30 pm.
HTH
