Just got back from my afternoon ride the trails have dried out nicely since last week and are just about perfect, a few more days like this and they’ll start getting dusty.
I’d just follow the road from Stowey up to the top (Dead Womans Ditch) the road climb will be bad enough, any bridleway climb from Stowey is sure to be most unpleasant.
From Dead Womans Ditch car park the stuff to the North (towards the sea) tends to be more flowing/longer, and the stuff to the South over at Triscombe is more shortish/sharp/steep.
Try and find Somerton Combe, on of my favorites, and as Jambo says Smiths is good but it dumps you in the middle of nowhere with the choice of one of two brutal climbs or a few miles on the A39 to get back to some decent riding.