In Resident Evil 4, you take on the role of Leon S. Kennedy, a government agent who previously appeared in Resident Evil 2. Tasked to rescue the President's daughter, who's been kidnapped by mysterious villains, you find yourself chasing leads in the backcountry of Spain, where a sinister threat arises, not just against a single kidnapped girl, but against the entire world. Although the Umbrella Corporation is a thing of the past, as are the zombies that infested the previous games, you'll still have plenty of people in your way here.
In GameSpot's guide to Resident Evil 4, you'll find some general strategies to help you out, as well as a complete walkthrough for the game, complete with video coverage of all of the major boss fights. In addition, the unlockable features here are all covered, including the secret weapons and the two major additional gameplay modes: Assignment Ada and the incredibly fun Mercenaries.
Since this guide was originally written for the GameCube version of the game, the Separate Ways content is not covered. Note that most of the mentions of the controls are also based on the GameCube version, so you may need to adapt a bit if you're playing on the Playstation 2 or the Wii. For the most part, though, the content should still be applicable. Enjoy! Ammo Conservation: Resident Evil 4 is blessedly not quite as intent on making you hoard ammo as previous titles in the series have been. Due to the fact that your enemies will often drop ammo when they die, and that ammo is more abundant overall, you're not going to have to worry too much about it. If you don't have to, though, it's best not to go hog wild with your ammo expenditure, especially for weapons like your Broken Butterfly and TMP, because those are the ones which you're most likely to use during boss fights
Using Chokepoints: The one thing you're going to need to learn to really be successful in Resident Evil 4 is the art of positioning. Your foes aren't going to politely wait for you to face them before they attack you; if you run into the middle of a group of foes, you're going to find your ass getting kicked well and good by the enemies behind you unless you find some way to get all of your targets on one side of you. The best way to do this is to find some kind of bottleneck or chokepoint and position yourself on the opposite side of it from your enemies.
Doorways are ideal for this purpose, especially when there's only one entrance to the room or hallway in which you're standing; since everyone will be coming at you from the same entrance, you'll be able to easily anticipate where they'll be after it opens up and position yourself to shoot them accordingly. What's more, the ganado door-opening animation is almost always the same, save for special enemies like chainsaw freaks and chaingunners; they'll tap on the door, bang on it twice in rapid succession, then slam it open. Since this takes a few seconds, there'll be more time for the rest of the enemies on the other side to group together around the door; if you're standing on the opposite side of it with your shotgun at the ready, you should be able to blast everyone there in the head before they get a chance to attack you. After you have a few chapters under your belt, you'll start running across Plagas-infested ganados. When you hurt these guys enough to kill them, they won't die; instead, they'll sprout a giant tentacle out of their head, looking like something straight out of the seamier side of an anime shop. While these fellows will take a bit more ammo to kill than normal, there are some tips you can use to help you deal with them.
The first rule is to keep your distance. This shouldn't be too hard to accomplish, though, because you'll hear a distinctive sound when a tentacle sprouts, and will be able to run during the interval between it popping out of the neck of the ganados and when it achieves its full form; during this time it won't be able to damage you. When it does reach full size, though, most tentacles are capable of attacking from a distance, so you'll want to be well away from the ganado before this occurs.
The second rule is that tentacles dislike light. Thus, a flash grenade will automatically kill any tentacle creatures within radius of the blast. If you've managed to sprout a bunch of tentacles, then flash grenades are a great way to deal with them all in one fell swoop. (They'll rarely occur in numbers larger than two, though.)
The third rule is that, although tentacles look intimidating, they're really not that much more difficult to deal with than ganados. They can't move much more quickly than at a slow shuffle, so as long as you have room to maneuver, you should be able to keep them away from you without a trouble, and they're still susceptible to the same ammo that their mundane zombie-like friends are. The main trouble occurs when you hit tentacles on the neck portion of their body; this can cause them to stagger in unpredictable ways, and sometimes they'll stumble forward into a position where they'll be able to attack you, even if you were previously out of range. Be careful! By hokage posted by me!