My 3 1/2 year old is a LP addict (must confess I love the Horrocks/ Clary combo myself ;-) and we were delighted when she was given this jigsaw set for Christmas.
It contains two jigsaws, which are both the same size (about the size of an A4 piece of paper), one with 12 larger pieces and one with 24 smaller pieces. What a great idea - it means the puzzle has entertainment value for a longer time! Once the large piece jigsaw has become too easy, there's something else in the same box to challenge.
We had a lovely hour or so sat down doing these together, and it was really nice to switch off the TV for a while!
I would say this is suitable from 3 to 4 1/2 or so.