Welcome to the world of sheep!

Firstly I would recommend that you buy a copy of the Sheep Book for Smallholders by Tim Tyne, this is an excellent book and has helped me a great deal, it also goes through the seasons and what you need to do when.
Secondly how old are your ewes and are you going to breed from them? Do you know if they have been vaccinated before?
If they are already vaccinated then they will need one booster per year, usually done a few weeks before lambing in breeding ewes. If they are not vaccinated then they will need a first injection then another 4-6 weeks later. Then after a yearly booster per year. Sheep are most often given Heptivac-p.
Some people will worm regularly but the best option is to get fec tests done and worm accordingly. This will also depend on how "clean" your land is and weather you are rotating them.
Hope that helps!