A barb that can level by itself in normal isnt to hard to pull off...even in NM its easy I guess but in hell it gets very difficult.....a barb is the worst choice to level by yourself......but if you insist on it then WW is usually the best choice but until your level 30 you have to basically use level one bash on everything....which really sucks so ill give you my build I used when my net was out and i was bored
Max: bash, concentrate(your main skill), battle orders(always use this to buff up your life before you start killing shit), Mastery(its up to you what you pick but Id go axe or sword)
Always make sure to put one into increased stamina and speed, also put a bunch of points into iron skin and natural resistance until they start giving you less returns per skill point. and as always ONE TO battle command.
Pretty vague guide and wont work for serious pvp at high levels but it should def get u to hell and even though hell maybe(i didnt go past NM)
WW is great if you have manasteal, but on bosses its not entirely effective.
and if you dont have manasteal then on mobs your not gonna get many hits off before you run out of mana. whirlwind is good at higher levels.