I'm going to put this here since I cant find a dedicated Dead Rising 2 thread and I can see that a lot of people have picked this up since its free right now on XBL , its mainly just a few notes and hints (only one spoilorish thing that i'll put spoiler tags on)
Okay - my suggestion would be to play the game through twice , the first time play it and just focus on the main missions and the 2nd time go and try to do the side missions as well.
I played a while with some other people yesterday (the first time I'd tried the multiplayer) and it made the boss fights *much* easier (it does help that i'm at the max level and can carry about 12 items) so if you are stuck then fire out an invite and get someone to help.
Although you get guns in the game (if you know where to look) they really are not worth the time to use them , I almost exclusively used blades (the swords off the wall in the casino are a simple and easy weapon) , and for boss fights using a combo weapon with blades is the quickest way to knock their energy down.
Also - when your playing at the start its great fun to just run around and dispose of zombies in interesting ways - but when you want to do the missions just ignore them and run through them , it takes a bit of practice but you should be able to run through groups without much of a problem and if they swarm then a jump kick is normally all you need to clear a path.
Although you can stock up on magazines which are as effective as the books in the first game you dont really need them as the weapons are so easy to come by.
A few simple combo weapons which are effective are :
Knife + Boxing gloves (boxing gloves are in the window of the shop to your left when you come out of the first tunnel and there is a bowie knife on the top of the paper stand nearby) - this is probably the best weapon against most bosses.
MMA gloves + nails (sports shop for the gloves and nails are everywhere) - another quick and effective way to take down bosses
Baseball bat + nails (both inside the first room) - a really quick and effective weapon for normal zombies but a bit too slow and underpowered for bosses
Axe + Sledgehammer (axe in the safe room , sledgehammer just at the door to the first mall) - a very slow weapon but good at wading through zombies (for a *lot* of PP) , hold down B to just spin around and knock them all down , you can use this on bosses but remember that your weak after using it for a few seconds and if they go into their animations they are probably going to knock you down.
Remember you get *more* PP for killing normal zombies using combo weapons if you want to level up.
Drinks :
Most drinks will give you back large chunks of health (orange juice and milk being the best) , but you should also look at the drink mixers in the various bars , typically add alcohol + a snack food to get a potion which will give you full health back (and make sure you have at least one before going into a boss fight) , you can also use the white one (quickstep) to double your speed to get to specific events if your running out of time
Zombrex :
At the start it seems you'll be running short on this but there is a lot of it around , some people will give you it for saving them and there are a good 4 or 5 just in the environment , two quick ones below
ZOMG Spoiler! Click here to view!
In the casino with the ribs bar as you enter - go upstairs and jump along the light fitings to get to an area with a gun , some cash , a book (gambling?) and a Zombrex
In the casino with the pyramid climb up the side of the pyramid to get a zombrex at the top
The hardest fight in the game is about the end of chapter 4 - how I managed it :
ZOMG Spoiler! Click here to view!
The fight against the twins , you only need to kill one but they will both take you down really quickly - stock up on health potions and dont be afraid to grab the alcohol around the room even though it will make you throw up - I went in with knifegloves and took a lot of damage but also took a freedom bear (teddy bear + machine gun) which i placed in the middle of the dancefloor - so when i ran around the area it shot at them - it did fall over a lot so you do need to keep resetting it but I found it did a lot more damage to them than me hacking away.