You get a cup of tea and a cake with your landing fee at Sandtoft. Haven't scanned what everyone else has put but if it's park and ride you want Cambridge has park and ride just outside the airfield. Bit dear to land at Cambridge (£25 last time I went) but worth going early to have a full day in Cambridge.
Good caffs at Sherburn, Fenland, Leicester, White Waltham, Sandtoft, Breighton at weekends.
Also Cosford aerospace museum is worth a visit, very good caff/restuarant there, don't know what the score is for 'civvy' aircraft flying in there though.
Elvington museum is excellent and has a good restaurant. You def need PPR there as they have events on the runway.
Sleap I have been told is very good and has some sort of aircraft wreck museum there open at weekends.