try www.manxbmd.com for some dates marr/births - also try www.imuseum.im for BMD(birth marriages deaths) dates - a sub to the newspapers should give access to reports of marriage etc - the imuseum papers cut off c.1960 so later BMD events need researching in person via microfilms at Manx Museum

The 1911 census is available online tho you may need buy a sub but once you get back to the census you can trace back via the decennial census to 1841 (several on board usually help out here if you have problems)