The internet is a sea of resources, but these are the ones I use most frequently. Worth checking them out if you are not already familiar.
Essex Society For Family History. Including a very handy Essex Parish Map here.
FreeReg. Parish Registers – 3 million entries for Essex.
FreeBMD. The Civil Registration Index. Essential for ordering certificates.
FreeCen. Free census records, primarily 1861, 1871 and 1891 for Essex.
The Essex Records Office. With a searchable archive.
The National Archives.
The British Newspaper Archives. Huge resource, lots of free content.
Beards Of Essex 