Hey there's two main primary schools in Skerries. St Patrick's is in the town centre, near the community centre and would have been seen as being the slightly more desirable school. Realt Na Mara is in Mourne View estate. I went there and found it a great school, but because of it's location it tends to attract a few unsavoury types. (Mourne View is a former council estate, though it has improved a lot in recent years). Both of these schools feed into the Community College (formerly Holy Faith/De La Salle) though girls also have the option of going to Loreto in Balbriggan.
There's loads to do for kids around Skerries - the Harps is a good GAA club, there's a soccer team, there's a hockey team, there's a tennis club, there's an athletics club there's a fair amount going on in the community centre too and the beach is always there. I grew up there and I think it a good a place as any to raise kids.
The only montessori that I know of is on the Station Road and it has a good rep. Pretty sure there must be more but I am not sure where they are.
Nearest cinema would be in Swords or Balbriggan.
Let me know if you have any more questions.