It's all the income the League takes in from ticket sales, merchandise, concessions, parking, tv deals, etc. It's essentially everything the League earns (before most costs).
HRR is the crux of the entire lockout. Owners want to split HRR evenly - 50% owners, 50% to players (as governed by the salary cap). Players currently earn 57%, so this would cause a reduction in salary cap, or rollback in salaries.
They also apparently want to redefine HRR to include less. So players receive a smaller portion of a smaller pie.
12 Team H2H League - Keep 6 (+5 under 23yrs)
G / A / +/- / PIM / PPP / SHP / SOG / W / GAA / SV% / SO
C - Thornton, Tavares, Laich(L), J.Staal(L), Smith, Adam
LW - D.Sedin, Gagne, Dubinsky(C), Doan(R)
RW - Malkin(C), Perry, Hemsky, Vrbata, Read
D - Keith, Karlsson, Carlson, Girodano, Girardi, White, Larsson
G - Rinne, Varlamov, Sanford, Elliott
Setting up the play.