Been there a couple of times, I'll share my experiences there but forgive me for egg-sucking lessons!
The ATC number is in Pooley's for PPR, just gave them my A/C info over the phone and they didn't have any problems.
The general format seems to be that you land and taxy as directed to park at 'Fylde Park' which is a small grass area, well marked in the flight guide. No handling agent needed, park up on there and then you have to walk off airside. Now, I can't remember exact directions off the top of my head, but if you head for the airport fire station they should open the gate for you. You will then find yourself outside the airport, and need to turn right to enter the main terminal building. It's only small so you can't really go too wrong. Once inside, go to the information desk to pay your landing fee (£10 for a light single I think?). They can also print off weather info there too if you want. There is a small cafe, not much to write home about really.
When ready to depart, go back to the info desk and they will let you use the phone to book out with ATC, again a very simple process. To get back airside you need to go through a door opposite the cafe marked something like 'Flight Crew Only' (or something giving an equal sense of self importance!) and in there you need to go through a metal detector/empty your pockets type thing (a bit like going through to a departure lounge) but the door from there leads you to airside. There should be a couple of security staff in there who can direct you, but generally it's a case of following a line painted on the ground back to Fylde Park, where you just start up and get further instruction from ATC.
Quick word of warning which may throw your navigation off slightly - both times I'd approached from the south with a view to transiting Warton MATZ direct to the field, however on both occasions I got told to standby by Warton for a while before they eventually told me to head for Southport pier and fly not above 1000' from there over the Ribble estuary towards Lytham Pier. Maybe they were just busy, but obviously that's the sort of thing they may ask. The first time, however, they handed me over to Blackpool once I was inside the BPL circuit and BPL hadn't heard of me at all, which lead to a heart-flutter type moment so I would check that they are arranging a handover!
Hope some of this helps, and I'd welcome some other input too (eg Was going past the fire stn. the right way out?!)
A38