There’s lots of training sites and a lot of opinions about the best one/way to do this, but I think doug polk’s website upswing poker caters to a broad range of skill levels and is the one I’d personally recommend (warning though the site itself is awfully designed). Nothing is really free out there I’m aware of unless you spend a lot of time discussing things in poker forums, which I wouldn’t personally recommend.
The Raiseyouredge free course is a good basic/starter course to gain a beginning level competency of modern fundamental strategies of today’s tournament poker. Note that most of these types of courses/sites do mainly focus on tournament poker. Raiseyouredge has an excellent rep, especially in the online scene.
