When you first arrive at the front gate there will be a child that will take you to Dave, after you finish talking to Dave, kill him and take his key and use it to open the safe right next to him. In the safe there will be a rifle that is called the 0l'painless. the rifle does 21 damage but it's way better than the sniper and a lot easier to repair and find ammo for it.
Strength - Megaton - Lucas Simms House
Perception - Republic of Dave - Museum of Dave
Endurance - Deathclaw Sanctuary - Deathclaw Sanctuary Entrance
Charisma - Vault 108 - Cloning Lab
Intelligence - Rivet city - Science Lab
Agility - Greener Pastures Disposal - Office
Luck - Arlington Cemetery North - Arlington House
Skills:
Barter - Evergreen Mills - Market Bazaar
Big Guns - Fort Constantine - CO Quarters
Energy Weapons - Ravenhold
Explosives - WKML Broadcast Station - Sealed Cistern
Lockpick - Bethesda - Bethesda Offices East
Medicine - Vault 101 - Dad's Desk
Melee Weapons - Dunwich Building - Virulent Underchambers
Repair - Aerefu - Evan Kings House
Science - Vault 106 - Living Quarters
Small Guns - National Guard Depot - National Guard Armory
Sneak - Yao Guai Tunnels - Yao Guai Den
Speech - Paradise Falls - Euology's pad
Unarmed - Rockopolis – Head directly west from Casey Smith's Garage, look for tattered banners strung up.