Hi Andy, I don't recognise your model from the recent Billing kits but I do remember a progress kit from a long time ago, is it an old kit? I ask this because the wood for planking may be old and prone to splintering.
If you put planking in this sites search box you'll get some help by reading the various replies. You will also find that sometimes opinions vary as to the best sequence, here is mine for this type of hull.
Soak or steam planks to make them pliable 2 at a time, one for each side of the hull.
Ensure the keel stays straight and true as you apply the planks or you'll get a twisted hull.
Put first rows of planks on, starting at deck level so you'll have a neat top to the hull.
Then put planks along the keel, working up the hull row by row.
You'll now have an odd shaped gap to plank between the rows, shape planks as you go, you'll also have odd size planks, these are called stealers. Work steadily and methodically, it's a lot easier than it sounds.
That should get you started, ask again with any problems.
Charles