This is a vital aspect of the game (and helps you to be competitive and avoid getting your team into financial ****).
The original post (which I've copied and pasted below) is not my work but it is sound advice.
Other points to remember.
1.
DO NOT USE THE RENEGOTIATION WIZARDThis is simply a fast track to a massive financial millstone around the neck.
2.
DO NOT IGNORE CONTRACT RENEGOTIATIONYes, it's the dullest part of the game. Get it done in pre-season, even if you only do five to ten players per turnspin.
3.
PRIORITISE AND STRATEGIZEPrioritise the key players in your team but strategize on how long they can stay relevant.
> Players tend to regress after the ninth season and in particular for the fundamentals of speed, strength and acceleration.
> Decide how long you think a player will be viable as a starter or as a backup
>
REMEMBER: Bonus payments have to be paid, even if you trade the player OR he retires. Therefore signing a 12 year player to a six year contract may ease your cap space today but it can cripple you down the road as 'dead cap'
> A player with a low salary is 'easier' to trade
ALWAYS CONSIDER A PLAYERS CONTRACT WHEN TRADING> Always consider cap space down the line when bidding for players in Free Agency.
A league with teams that have teams with well maintained cap is super competitive and therefore more fun to be part of it.
Contract Negotiation For Dummies
And remember that each new Base Salary MUST increase by at least 5% each year.