Before you start manager mode just create about 3 or more players with everything 99 as there stat, prefferably strikers, then add them to the team you want to be in manager mode, start manager mode as that team then fill in the details [basic] put the excellent players up for sale, but play them and they'll be worth more, after that someone will put an offer in for them, about 45 million - 60 million!!
If you want to be the best at manager mode, go to edit player in one of the menus and edit a player from any team. Put all their stats up to 99(don't worry about the keeper stats of outfield players) you can do this as often you want to whichever player you want. If you do this save and make a new manager on manager mode. Chose that team that you chose to make al 99s and your team will all have stats of 99. They will also be worth alot of money on the transfer market
The best team in my opinion is GK Cech RB Zambrotta CB Terry CB Cannavaro LB Carlos RM Ronaldo CM Ronaldinho CM Kaka LM Robben CF Rooney CF Shevchenko.I have this team in manager mode and I never lose matches.Ps buy theo walcott he goes up to 99 he is brilliant.
To be able to do the following you must be in 'Manager Mode' as it will not work in a match. Save the game and quit 'Manager Mode' then load the game up again and your players stamina will be almost fully refilled. This can be repeated as many times as you want to keep your team's stamina full.