Hiya, constantly in games, black trades down to a simplified pawn structure (usually in my favor) that makes it hard for me to figure out how to continue.

Now I don't think this position is all that bad, especially considering my rooks.  The game ended up in my win after he blundered into a position where I checked his king into a fork.  I can generate an attack if those pawns are advanced, but I simply don't know how to do that unless they are already somewhat close together.  Could someone give me some ideas on how I should have continued, prehaps suggest a book that would give me these ideas, or show me games where a position relieved of all tension is converted into a win?

To me, it seems that whites d4 square is kinda soft. Black can generate some pressure against the white queenside pawns via nb4. I don't really see that either side has a decisive advantage. I'm thinking maybe black should push his kingside pawns a bit, putting some pressure on the white bish, and also give his king a route to solidify the centre. Without worry of backrank mate, Black can mobilize his rooks before they get tied down to defence.

I would play 1 Nd5.  White looks to have a reasonable advantage there, I would say.  Since a position with symmetrical pawns doesn't have any pawn breaks, your best bet is just to keep on improving the position of your pieces and hope that eventually you can infiltrate somewhere (like the 7th rank) and win a pawn or two--without of course giving him too much counterplay in return.

These kind of tensionless games drive me absolutely nuts!

I think that white can disrupt black's pawn structure but I'm not sure if he can unbalance it enough to make a difference.  Expanding on tonydal's suggestion, here's one possible continuation that may or may not begin the process of prying something positive out of the position:

• Nd5 Nd4 Rd2 Rfe8 Rxe8 Rxe8 Be3 Ne6 Bxb6 axb6

Cross your fingers and hope for inaccuracies from your opponent.

1 Nd5 Nd4 2 Ne7+ Kh8 3 Nxc8 Nxe2+ 4 Rxe2 Rxc8 5 Re7.