Everyone's looking for free developer help these days...
"I have very little experience so I need help."
Get some.
"Things I need in game"
"Most troubling to me is how to sim stats"
.... well if you're doing a basic web application (php + mysql for example) create a database table to hold the values you'll need, create your rules, and use php to generate the player stats. Build a little php app to generate 'x' number of players to populate the database.
Have fun though - you'll need to sort out players abilities, what team they're on. You might want to be able to store several leagues in one database like the nhlpa games.. try not to over complicate it the first time around - just keep it simple and make it work once, THE EASY WAY. If you can do that and it works and you like it? Then spend the time recreating the system with a revised design. You'll have more improvements in mind and a better idea of what's going on if you finish. (and be less discouraged - I know what it's like being a beginner and getting into projects that are way over my head in the past)
"adjustable Roster page"
Again if you're doing this with php/mysql (html, css, and javascript are naturally implied) this is best done with html and javascript. Look up tutorials on dynamic form fields or dynamic form lists.
The rest is up to you.
Alternatively you could do this in flash.. if you have the time, money, and expertise. But it sounds like a challenging enough starter project for html/javascript/css/php/mysql.
Good luck.
CodyBane++,
web application development