GEORGE GARSIDES tutor is probably very good,but having a knowledge of music theory can be very useful,
so you start on one row as Brian advocates[that makes sense, no good running before you can walk] ,you get to a certain standard but cant get any further,this is where a little musical knowledge /theory is useful,youcan start improving your right hand by using octaves or thirds or other two note harmonys[if they sound good],if you have no musical knowledge you wont know about these possibilities, unless your naturally very musical .
music theory is not crap,knowledge is the key to understanding,understanding helps the pupil, to progress more rapidly, 99 percent of the time.