Going there for the first time in a couple of weeks, family holiday etc.

Taking bikes, seems to be quite hilly with a fair few bits of lane and bridleway about, anyone got any routes?

Also, what about for kids/families, any nice places to take the bikes for them?

The coastal path form Beer to Sidmouth and back is fun (if not strictly legit)if you are taking MTBs and kids, if you are taking a road bike there are a lot of sharp hills in the area, great fun!

go to the quantocks or puddletown forest for decent MTBing.

apart from down by the sea front, I can't see Lyme being much fun for kiddies to cycle round.

Don't bother with puddletown at the moment, it's rubbish coz of forestry work they've done.
I'd be wary of trying to do coastal paths due to it being the busy summer hols period & walkers everywhere.

You could head over to Portland for a good blast yourself.
Or take them up to Haldon (Exeter) as there's a purpose built trail centre there that has a couple of good trails for families.