Let me show you how to hump without making love.
I wish you guys saw this and posted this stuff earlier.
I got 5th. I lost the first round where we picked (sniper). Second round I apparently lucked out and got the best character according to everyone (Some fiery red orc looking staff guy, he had this spell that would deal damage over a period of time, usually killing them before they could run back and heal. he was rape.)
Anyways I always went power treads - yasha - sange - and If I could make it the sange+yasha thing. The crazy open game play these items give is prompting me to reinstall WC3 and try my hand at it.
I play DotA everyday and I can sometimes be the best... then sometimes the worst.
I primarily like to play with Spectre, Dark Seer or any nuke-based unit. I usually go for something that will enable high DPS (damage per second) while keeping it helpful for more than that and let the unit go all out.
If you wanted to play with Sniper, I would have suggested a Mask of Madness, Treads and Lothar's Edge as your early game build. If the game lasts longer than that, add a Butterfly, Sange+Yasha and Buriza. This would make you not only have good Survivability, but also increase your DPS through the roof.
Mask of Madness not only gives you lifesteal, but can increase your attack and movement speed for relatively no mana and has a short cooldown. Then you have Treads, the basic item that will make you better all round. Then Lothar's Edge gives you extra damage plus Wind Walk with is amazingly handy.
Butterfly is the best all-round item a ranged Agility-based unit like the Sniper can get. It makes enemies miss attacks, increases his attack speed and increases his damage. Sange+Yasha will increase your health, your attack speed, your damage and your movement speed. It's orb will be overridden by Mask of Madness, but thats all good. Then Buriza, one of the best items around, will allow you to dish out damage like crazy. It gives additional damage and a critical, so with all of your increased attack speed, you shouldn't have a problem dealing criticals often.
That, in my opinion, is a good Sniper build. Even though I have never actually sat down and played him myself. As for his abilities, I would get his range and scatter first. Since his ult isn't crap, always level it ASAP.
None.