In my kitten's log book, I put the following.....
Photo of pregnant mum
Time of birth
Breech or head first birth
Photo at birth
Weight everyday, then after a few weeks, weight every week
When first teeth appeared
When eyes opened
Colour of eyes
When ears opened
When their first walk outside the nest was
When first had solid food
When first litter trained
When first examined by a vet
When had first vaccinations
Paw print (DO NOT use anything toxic! I used a non-toxic childrens paint and washed it off the kittens straightaway after taking the imprint, making sure that it was only the pads of one paw that was covered (as opposed to covering the fur with paint) to take the imprint.
The log book now makes a lovely souvenir which i like to re-read everynow and then!
I have the template of the kitten log I made up myself (with fancy pictures (taken from Microsoft Office so no copyright issues) which anyone can use to insert their own kittens details. PM me if you would like a copy (is that ok mods?)