I got promoted with Bradford after the 1st season, players that helped me were:
Bernard Mensah (Watford released him). Good poacher who got me plenty of goals.
Davide Petrucci (Man U released him). A really good AMC who can be used as a playmaker as well.
Oliver Norwood (Offered to me by Man U for free in 1st season). Still in my squad now after 5 seasons, is considered a leading star for the championship. (Central Midfielder/playmaker)
Jamaal Lascelles (Free transfer?) A good young DC, develops well after a few seasons but is more than good enough for League 1 at the time in my opinion.
Jonny Gorman (loan from Wolves). Decent right winger who I've now bought. Has developed really well and plays regularly in my first team now in the Championship.
Thats all i can think of at the moment, I suspect most my other young quality signings at the time were newgens. I'll add more later if I remember any more.