no booking required
hotels depends on your budget (eg the Sefton is quite expensive but nearest big hotel) - see those advertising on this site (see tourism) or try gov tourist office - see www.gov.im - the Manx museum is at the top of Crellin's hill - any B&B ion the Prom will be within walking distance (10mins + use of the lift in the multi-storey carpark - or get one on Bucks road then walk down hill.
Do as much as possible before coming (eg all parish records/wills are on LDS films)