I don't know much about dark or steel types, but I run a Water / Steel, a Fire / Grass, and an Electric / Psychic.
Until I can get access to my cards, I am going off of memory here. You're going to want 7/7 on the energies for the Grass / Fire deck. Maybe 9/5, but never more on either end.
http://stop2shop.com/rr-045.html <- One of the best Grass Pokemon cards you can have, and it's CHEAP. ($0.40 each.)
Right now I can only give you general advice until I get my Pokemon cards from wherever they are hiding. Don't run more Pokemon than Trainer cards. Because if you do this, you might end up etting Stage 2 and 3 cards that fill most of your hand, and it's easy for an opponent to discard it. Run a good amount of different Pokeballs, Potions, and cards like Professor Elm's training method. Stop2Shop is a GREAT resource for buying cards. I'd bought a Heatran from them for $3. 40 base damage attack, plus 40 more for each heads you land, and you can flip as many times as the amount of energies he has attached.
I hope this can get you by for a day, as I should be able to help you more tomorrow. :P If you'd like, shoot me a PM and we can continue.