Well there's a nice intro to the community (NOT). So, rushing Warmog's isn't any anymore viable on Vi than it is on any other champion (Which is to say its not viable and completely useless). But figuring out a real build depends on which role you like to play Vi as... Vi can be a powerful initiator and functions well as an offtank, or she can enter fights late and storm the back line, going for carries and squishy mages. The former will see you building heavy defensive stats and going for damage later so you can survive fights and pump out damage and disables for your team. The latter build gives up survivability in favor of more damage and outright killing potential.
I personally play Vi as a jungler exclusively because I prefer other champions solo... Well actually I only play Singed solo top. But Vi is certainly a good solo top, you just need to watch your match-ups to make sure you're not going against a strong anti-melee champion (Riven, Jax, etc...). I run 0-21-9 getting resistances, Mini-Tenacity and Increased Buff Duration. But I would probably take more damage if I was in solo top.
Whether you go jungler or solo top with Vi is up to you, but your build depends on you AND your team. A tank build will give your team a massive edge in fights because Vi is such a great initiator. Pop your ult and slice up the enemy team and dash to a carry and smash up their face with your massive metal gauntlets. Break enemy armor to boost your allied carry's damage while tanking turret rounds or drawing enemy fire.
To build... grab a comfortable mix of armor and MR to counter the enemy team from two or three of the following...
-Ninja Tabi or Mercury Treads
-Spirit of the Ancient Golem (Don't buy with Treads)
-Iceborn Gauntlet (Don't buy this with FM)
Round out this build with some mid to late game damage and more survivability with...
The bruiser build rolls a bit different, I would recommend this as the better one, but its a little bit harder to master as you are a bit glassier.
Grab Mercury Treads, Black Cleaver and Frozen mallet ASAP in whatever order you like. Usually grab Tier 1 boots, then Phage, Treads, Brutalizer, finish the Mallet, and then Black Cleaver. From there, either drive home a win with Blood Thirster and Maw of Malmortius. Or hunker down for late game with Sunfire Cape and Banshee's Veil and toss in a Hexdrinker for damage or maybe toss in a Guardian Angel otherwise.
So this isn't really what I go for every game (I wouldn't tell you all my secrets anyways). But its a decent start to get you rolling and help you set up your own build. Try out some other Items if you think it looks good on Vi, but make sure you maintain a stable balance between survivability and damage.