Anyone know where to find one early on? Or what is the earliest you can get one?

go get ratslayer from the broc flower cave

Go to Camp McCarran, in the 1st recon tent on a top bunk is a sniper rifle in poor condition.

Gun runners generally have one or two for sale as well.

You can get a Hunting rifle at the 188 trading post South of Vegas. either from the Gun runner under the bridge(if he will sell to you, 40 guns skill needed) or the Arms dealer off the back of the lorry up top.

You can find one of the best sniper rifle's as above, in Camp Macarran, on the top bunk of a bed where the 1st Recon guys hang out, but its in pretty poor condition, but still beats the others avaialbe at the time of the game. I'm level 15 and it still isnt in the shops.

If your lucky enough, the Goodsprings merchant will be selling a Varmint Rifle Night Scope. Slap that on a Varmint Rifle and that's the earliest you can get a sniping rifle. He'll also sometimes have the silencer for that weapon. I've been able to do this right at the beginning of the game. The AP cost of the Ratslayer is ludicrous - you're better off modding your own Varmint Rifle.

Getting Ratslayer is high risk (in comparison). And if you can mod a Varmint Rifle at the start, you'll be good to go for a while.

Others have already addressed where to get an actual Sniper Rifle.

Definitely the ratslayer. While sniper rifles are more powerful, it's simply not necessary until you are against much tougher opponents - considering that using it most of the time would cause it to constantly need maintenance (it degrades quickly). Ratslayer is light, awesome range, plentiful ammo (with AP ammo available) and has a high crit multiplier. It's not great in vats as it uses over half of your action points. You can sneak attack one shot a lot of enemies with this gun.

edit - I also thought at first the modded varmint was a better deal than the ratslayer, but the laters damage is higher, and has a 4X crit chance which just makes it much more deadly. Just use it out of vats, which isn't a big deal if you're sniping anyway.

Take that rifle to the Major at outpost in lower left part of the map (where Cassidy is) and he will repair it to 100% I believe.

Like GraniteDevil pointed out, Chet at Goodsprings carries most Mods for the Varmit rifle. If he doesn't have what you're looking for, fast-wait 3 days and check again.

If you're playing on HC and fast-waiting for Chets mods, remember to stock up on food and use Victor's shack for water and sleep.

If you're in the neighborhood of 188, you can get a hunting rifle for free if you check out the train on the rails near Boulder City. There is a skeleton on the ground next to the train with a hunting rifle next to it. Obviously it will cost you money to repair it.

Ratslayer is a solid choice, especially for stealthy characters.

Like DocHoliday says, the bonus critical damage and noise suppression can make up for its weaker base stats. Additionally, ammos is plentiful and cheap, you can repair it easily with inexpensive varmint rifles, and the night scope helps a lot in darker areas.

Edit: Having gear that boosts perception and critical chance makes it even better.

Hunting rifle is a good first sniper rifle, especially if you can find a scope.

As somebody mentioned, if you're willing to make the trek, you can find the unique "Ratslayer" in Broc Flower Cave.

There's also the broken 1st recon sniper rifle at Camp McCarran (if you can make that trek).

There's just one more thing to point out...

If you're going to be stealthy, you don't need to worry so much about crit multipliers. You want a 100% crit rate? Get into sneak mode and attack from [HIDDEN] status. Having a silenced/suppressed weapon will help you keep that [HIDDEN] status since hostiles will only be able to rely on sight to find you.

Ratslayer IS a good weapon... depending on how you use it. If you're a stealth sniper, you don't need to rely on it.

One thing to keep in mind, though, if you've taken the Wild Wasteland trait, is that the Giant Rats in the Broc Flower Cave are replaced by "Rodents of Unusual Size", and they are a lot tougher to kill than regular Giant Rats.

This is definitely true.

"Rodents of an unusual size" : reference to Princess Bride movie

Even if you don't take the trait they're no joke. A sub level 10 character will die to these things in 2-3 hits on normal difficulty. Took me several reloads to to get Ratslayer on my current character. If you already have a Varmint Rifle with all three mods then going for Ratslayer isn't worth it.

If you want max dmg out of a sniper riffle i suggest you find the named one( wich i forget the name off at the moment) in the sniper's nest, you need a lockpick skil of 100 to open the locker but its a badass sniper riffle

Early gun that requires Lockpick 100? ))

Personally I like La Longue Carbine early on more than anything else, including Ratslayer.

Whats early? I mean don't expect the best gun in the game at level 1, and all you need is about 83 lockpick + a book and some good mentats. My lockpick is always the thing i max out first, i mean how many times have to come across a safe, locker etc.. and you can't open it and say, bah i'll come back later, and then forget where it was, next thing you know you got like 20 places scattered around that haven't been opened lol.

If you max Lockpick that early, you waste points in the end because it's most likely before you have found all the Lockpick books... GOBI requires 75 in Guns, that's not early either. Early is something you can use without much hassle at lowest skill levels while you are still training Speech and Lockpick. Ratslayer and LLR fit best here.

Somewhere around North gate to Freeside in the Mojave proper is a normal sniper rifle, in good CND with some ammo, behind a hard locked door. Nice find for those that zoom up lockpick early. For those like myself that really don't.The one found at McCarren combined with the two you can get at Gomorrah will do the trick.

Coyote Tobacco Chew+hat+Mentats+Comprehension gives you 26 extra lockpicks

Early on my guns char just uses a fully modded varmint rifle.. one shots all the early foes VERY well from very far away.

8 shots night scope and silencer is very powerful at that point.

Thanks for the advice everyone. Mostly trying to find one to take out the deathclaws early on and get to new vegas faster. Short of a head shot, it takes two hidden shots and one or two close range with the sniper rifle to take one of them out, vermint rifle just does not cut it against those guys.