Co. Armagh Civil Parishes Map
Co. Armagh Roman Catholic Parishes Map
Co. Armagh GENUKI
Co. Armagh IGP
Armagh Ancestry (RootsIreland)
Armagh County Archives at PRONI
Special Ingredients - Record Finding Aids
Co. Armagh Church of Ireland Parish Records Finder
Co. Armagh Registry of Deeds Townland Indexes Timeline
The Armagh IGP page is a bit of a mish-mash of information - you have to pick out the local stuff from the national references repeated here, but at least it appears to be being worked on.
The GENUKI page appears to have a very extensive list of hyperlinks to many resources that look to be specific to the county and is well laid out to understand timelines for example.
The Royal Irish Academy's Historic Towns Atlas includes an edition for Armagh - the ecclesiastical "capital" of Ireland.