Really if you're playing anything pre Torment 3/4 basically any build is viable :p, I've played all the way through from normal to T1 using random builds like Pet Master DH, Melee Wizard and ranged Barbarian
Really just pick up a Crusader and play around with the skills as you level, you'll find a build that works well for you.
For leveling up you want good resource management and nice AoE. If you want ranged combat, just use Fist of the Heavens and Smite/??? or Justice/Crack. Leveling up should be an easy task, just try out all the new runes you unlock. You'll come across something good sooner or later.