Pripyat is a rather large and interesting place although you're not likely to see that much of it unless you specifically wish to. There aren't many items to be found except for rare artifacts and stashes - but the area can still be interesting to explore because it in many aspects resemble what some parts of the real city of Pripyat looks like; alot of the buildings and architecture, along with the general looks, has been reconstructed in detail.
As soon as you enter Pripyat you will be given the mission: Reach the power plant and you should be able to see a group of expert Loners just ahead. They all have Exoskeletons and high end weaponry. They are going to push forward into Pripyat, so accompany them and help deal with any dangers on the way. Heading down the street you'll hear them call out foes - look especially for enemies on the roofs and behind windows. When you move on, don't stray too far away from the group - there are snipers about and you'll be able to avoid most of them if you follow the group to the carpark. If you'd like to explore Pripyat after reaching the carpark keep this in mind - especially since most of the snipers are wielding Gauss Rifles which can tear you apart in a shot or two.
Don't worry too much about looting corpses or picking up artifacts as you can come back here later on - for now simply follow the group as they make their way towards the carpark. When you finally reach it you should have picked up an additional 5-6 PDA's in the vicinity - these are Monolith soldiers in the carkpark so proceed with caution, or just let the group deal with them. Once they've been taken care of your mission will be updated and you must now make your way towards Chernobyl NPP itself. Hopefully you met with Guide and the Doctor earlier in the game, which means that you have a mission in between, namely to reach the secret stash further ahead.
Moving north out of the carpark, beware there is a Gauss sniper on a roof further to the north and two more on your right side, one inside a broken building and another one on a different roof to the north-east - they can't see you yet, so worry about the first one for now. Move on and deal with any snipers that may have spotted you - either take them down or stay behind cover.
Pripyat is home to several secret stashes; all of them contain valuable items. A few contain very valuable artifacts, such as the Kolobok, or the Battery. Others contain AP ammo or high end weaponry. Fang's grave contains the one of a kind Exoskeleton PNB-4UZ and a rare Mama's Beads artifact. The coordinates of these stashes can be acquired in previous levels.
The Secret stash at PripyatEdit
The building directly north of the carpark is the place where you can find the stash, so make your way there. You should be able to find stairs going up just inside the main entrance. Move up to the first floor and down the hall - you should soon see a door with the number 26 on it. Inside you will find three important items - a worn manuscript (document) sitting on a shelf; a decoder sitting on a shelf in a bookcase, and on the couch you'll find the outstanding SKAT-9M Military Armored Suit. Be sure to pick up the decoder because without it you won't be able to access the "best" endings of the game.
The Monolith baseEdit
To the north-west of the building you can find the Monolith base. The base is the Pripyat sports center. There is a room with what appears to be a man-made sculpture representing the fabled monolith, although this is explained in S.T.A.L.K.E.R.: Call of Pripyat. Around it you'll see several Monolithians worshipping the sculpture in coma-like states. In the same room you should be able to find some nice artifacts, including several Night Star artifacts, a Moonlight (only there in the late evening and early morning), a Spring and a Kolobok. Refer to the video for the exact location of the room - there are likely to be alot of Monolith soldiers around so you may wish to express a little more caution than displayed in the video. The building also has a basement containing a Monolith Suit and a Monolith figurehead called Charon.
Eventually you should head north to the entrance to the Chernobyl NPP - you'll probably meet resistance regardless of which path you take.