1) You could search 'Niichts' on Youtube for some pretty informative and witty commentary on the game, but really, most of the guides you read probably won't be that helpful. You're gonna have to pick a lot of things as you go along. Know which class to pick at the right time. Medics and artillery classes are always helpful, Heavies are great at anchoring a push, Engineers and their teles are essential for large maps, and Pyros and Scouts work wonders on maps with many side-routes. Work on mastering the general strengths of each class before anything else, e.g. good sentry locations as Engineer, ambushing as Pyro, proper aiming as Soldier or Demoman, prioritizing heals as Medic, knowing when to retreat as Heavy (about half health is a good guideline for beginners). I would recommend you avoid Scout and Spy until you know the maps a little better. Always keep in mind, though, the more advanced abilities of each class, like the Pyro's airblast, Ubersaw opportunities as the Medic, stab-sapping/telefragging as the Spy, and the Soldier/Demoman's rocket/sticky jump, and practice them as and when you can; eventually you will get better at them. Rocket jumping in particular is a fantastic asset to a good Soldier, but it does take a while to master, so don't be disheartened.
So really, the best guide to TF2 is experience. Don't expect awesome kill streaks or tons of OMG-did-I-just-pull-that-off moments as the beginning - the game has a pretty steep learning curve, and more advanced players will likely dominate you often. But don't fret it! There will be rewarding times along the way, and know that as you get better and better, they will come along a lot more often than you'd think. :)
2)
http://fakkelbrigade.eu/chris/configs/
Give it a shot, I found it pretty helpful.