First of all t3h stats.
Spec. Attk.: 298
Spec. Def.: 298
Eh, average stats. HP Average, Attk.=Not good, Def.=Not good, Speed=Eh, SA=Average/Good, SD=Average/Good.
It's Special Attack and Special Defense are actually quite good. Thus, Venu is able to utilize moves such as Giga Drain/Solar Beam. It's Speed, Attack, and Defense are okay, albeit on the low side, but Venu doesn't really use his Attack unless it's coupled with Swords Dance.
Okay, t3h moves/movesets come next.
Venu, as stated, has nice Special Attack, which can be raised with the use of Growth.
He can also use the Sunny Day/Solar Beam/Synthesis combo, albeit not used much due to it be VERY risky, if the opponent's Fire-Type is not fainted, and still risky even if it is (Helping all the Pokemon that can learn Flamethrower thanks to Crystal).
Venu can also be on the Attacking side. Swords Dance will help Venu achieve this. The only downside to this is that the only good physical moves that Venu learns include Body Slam, Double-Edge, and Return. Not a variety to choose from, eh? Also, for some strange reason unknown to me, is the fact that Venu cannot learn Sludge B0mb...o_O;; I mean, it being part Poison-Type and all, that's just fucked up.
Venu is also used as what it's the best at; Sleep Mongering. This little bugger can learn Roar and Sleep Powder (And Stun Spore, making it a bitch to face with Spikes). This guy can do a lot of damage being a Sleep Mongerer/Double-Powder Mongerer.
And now, here are the movesets.
(The quote thing is a ripoff of oporaca's post )
The "I hope my ass doesn't get kicked by using this risky combo" Venusaur
-=-Miracle Seed/Mystery Berry-=-
The "I like to use my Swords and raise my attack to kick your ass with my limited variety of Physical moves" Venusaur
The "I am t3h 1337 sleep mongerer" Venasaur
Giga Drain/HP Grass
The "I am going to use Curse to look like a good PokeyMan" Venasaur
Double-Edge/Hidden Power Ground|Rock/Return
That be my p0st. Hope you esicellaly lie it