what is the stat distribution for a rogue and how do i get them to do more dmg with a dagger?

give many points in dex its give u critical hits

but since dex has been nerfed, all dex does not end up to be effective

currently, the built many players use is ~ 110-120 dex, rest into strength.
but this does not mean this is the best built.

for melee, these guides might bringt you some helpful information:

http://forums.d2jsp.org/index.php?showtopic=21698846&f=272

http://forums.d2jsp.org/index.php?showtopic=18067459&f=272

furthermore, you should check this for some basic knowledge:

http://forums.d2jsp.org/index.php?showtopic=24496799&f=74

and after reading, you might change your choice.

in my opinion, if you play melee as starter class, you should aim for fighters e.g. because they can wear heavy armors.
the problem in your case would be, that fighters can not wear daggers unfortunately.

rogues are excellent as hybrid ( check this guide for more info: http://forums.d2jsp.org/index.php?showtopic=13894977&f=272 )