Hello,
From what I can gather from G-INFO and various other places they have:
6x J31s (G-BTXG, G-CCPW, G-EIGG, G-JURA, G-LOVB, G-UIST)
1x F406s (G-LEAF and they also operate the 2x on behalf of the SFPA (G-SFPA and G-SFPB)
1x BN2 (G-SEIL)
1x J41 (G-TEXA with another arriving in the near future)
As far as routes go:
They do the newspaper runs for the Northern and Western Isles flying to Stornoway, Kirkwall and Sumburgh.
They have a PSO contract flight running between Inverness, Stornoway and Benbecula
They have another PSO contract flying between Anglesey (Mona) and Cardiff using a J31
The Islander will (eventually!) be used for flights between Oban, Coll, Colonsay and Tiree.
I think they also have 2x J31s flying for BAe beteen Warton and Cambridge and also do Oil exploration flights to Ireland (Cork, Shannon, Waterford) as well as to Norway (Bergen, Stavanger) and the Faroes (Vagar).
The J41 as far as I know will be used for BAe on the same flights as the 2x J31s (more pax!)