this is very true though there is no substitute for experiance use the board or books?more as guide lines do what you feel will be right. thus having said this, in a small cabnit grow your best bet would be to line the whole in side with mylar or spray paint a flat white, because cant use to much light in that small of a space this will make what every bulb you use stand out allot more... then yes with the scrog its very easy at a young age to start toping and using low stress and tie down methods to utilize your growth to maximum potetial... what plant strains will you be growing?