hmm.. prob not quite enough to fill your time everyday

but there are extras that can take a bit of time;

Training

do you keep track of your players stats?

i know you're not a supporter, so you wont have access to player cap levels, so it might be worth keeping track of players fitness trainings to make sure people haven't capped and you're wasting training points.

Also, it's worth looking at your player needs and builds and working out out how you want to train all your people, make sure they're in the right selections (this can take a surprising amount of time)

Scouting

There is some scouting to be done, but it can be limited depending on your personnel. Most people wont swap their lineups around too much unless they've got very good reserves to come into the required new positions.
However, that's not to say don't scout at all.
useful things to look for on an opponent are their previous games, you can see if they're a run/pass heavy offence, if you look at who on their opposing teams have been making all the tackles, this might give you an inclination as to whether they prefer to attack down a specific flank, if so, you might want to reorganize your top people to cover there.
likewise, you can look at the WR & TEs stats, you can get a good idea of who their top threats are and put your best coverage accordingly.

other than this, scouting can be used just for basic knowledge. use some of your scout reports on the key players from some of the successful teams, this will give you a rough blueprint of how you might want to train your players.

Transfer Market

the best bargains need to be found, and it's usually sadly through hard graft, take the time to go through all the young players available, if you see some cheap potential, try and scout them.
If you have aging players on your team, try and find young replacements that you can get now to start training to take over in a couple of seasons.

Like i say, there are some tasks you can do, but not really quite enough to fill everyday...

Thanks for the responses guys - gives me a few things to think about.

I appreciate the warning regarding money - but I think I am more than cautious enough to avoid going bust.

I think the time has come for me to become a supporter to see what extras that brings. As I have said before it's a little bit pointless having the 3 days free when you start, as I'm sure most people take longer than that to work out what the hell's going on!

With regard to adjusting strategy to your opponents playing style - are there any good discussions on this topic you could direct me to, as I am a bit clueless - my knowledge of american football comes exclusively from coverage on tv and that doesn't really cover strategy. The defensive plays on the Madden videogames also left me scratching my head.

I have only been on this game for a month, but with my busy schedule it is nice to have a game that you have time to take care of certain things during the week. I have seen other games where they simulate 1 or maybe two games a day. I just don't have the time for that so this is my reason for trying GI. So far I have found it entertaining.

One thing that can take alot of time is bidding on players and making sure no one jumps in to overbid you.