Even if i wasnt a Milan fan I would still say get Tassotti from AC Milan.
Brian Eastwick has always done me well. Used him in FM10 and now in FM11 and he's always done well.

I've also used Jamie Redknapp in later seasons, once Eastwick retires (Usually about 10 years in) and Redknapp seems to do alright. But Eastwick is my favourite.
di salvo, the ex man utd assistant. best i have found but neri is a close second
I used Owen Hargreaves-did brill for me
There's always the usual answer, search with the filter on Man management and Tactical Knowledge at minimum 15, you'll find 4 or 5 of them usually unattached
Moniz always did well for me on fm2010. havent been able to get him on fm2011 yet
Nigel Gibbs works wonders for me and is always interested in joining
Hans Jorritsma, pretty good + goes to pretty much anyone!
Steve Clarke is free agent and he is good, I take him everywhere i go.
Al Stewart is quite good and always does the job any where I have him at Liverpool but also at Crewe so he will sign for pretty much any team and asks for about £800 a week