Entering the Malvern Midsummer Marathon is pretty straightforward. It is organised by the Heart of England branch of the Long Distance Walkers Association (LDWA) and costs £10 to enter (without membership) by filling in an entry form available here.
Please be aware that entry numbers are limited, so get your form in quick if you want to take part!
You may wish to purchase the Malvern Hills and Bredon Hill OS Explorer Map which the whole of the route can be traced on. If you are looking for a hotel in the area then a good place to start is this site which gets the best price for local hotels.