What ho Bob.
If you're able to get into London town at any time, have a browse in Motor Books behind Leicester Square tube or they do mail order
http://www.motorbooks.co.uk/Most of the good (mostly American) Drag Racing and Hot Rod books are choc full of good illustrations and (again being American) won't show acres of flesh. Any book will have pages of text but there will also be lavish full colour spreads of fuel funnies and dragsters.
Having been to the Don Garlits Museum in Florida, I would recommend this book
http://www.motorbooks.co.uk/review.asp?bookid=65349 although it may be a hit too 'historic' and not hold the interest of a 7 year old.
This is a good hot rod book with plenty of photos
http://www.motorbooks.co.uk/notes.asp?bookid=68841I would suggest having a browse in Motor Books shop and looking for a large format book full of glossy colour photos, either of dragsters or hot rods.
As regards the Easter Thunderball, hopefully the weather will behave. There may be one or two Top Fuel cars there, most of the field will be alcohol dragsters / funnies, super gas, sportsman classes, motor cycles and one or two jet cars.
There's usually a full 8+ car eliminations entry of top fuel dragsters at the FIA Euro Championships round 1 'Main Event' on 25th - 28th May.
http://www.santapod.co.uk/calendar.php