Getting Started

This guide is for someone who has no idea of where to get started in emulation.
This guide is intended for someone using a Windows machine.
This guide may seem long, and I might make emulation sound more difficult than it really is. But give it a shot, it is really not difficult once you get the hang of it.

Definitions

ROM - Stands for Read Only Memory. This is the microchip inside of the physical game cart that contains the game program. The game is transferred, or "dumped", to the computer via a "reader" of some sort, and stored as a "ROM Image".
BIOS - Stands for Basic Input Output System. Similar to what you have inside of your computer. It basically tells the machine what to do. You may or may not need a BIOS Image for the emulator to run correctly.
Emulator - This is the program that acts like the game console that you want to play the ROM Image on. This is where the hard work of emulation comes in. Someone has to program an emulator to emulate/mimic the actual hardware of of the system, and "trick" the ROM and BIOS to think that it is actually running inside of a real game system. Luckily for you, there are many smart and generous people out there that are willing to spend their free time to program an emulator, so you don't have to create your own.

The Legality of Emulation

I'm sure that you have heard that emulation borders on the edge of being illegal. If you own the game and system that you want to emulate, then it is perfectly legal. Most people feel that emulating old "retro" systems should not be considered illegal even if you don't own the system or game, because you simply can't find these in the store anymore.
You are unlikely to have the FBI knocking on your door in any case. The most that would possibly happen is having the IDSA or Nintendo send you a cease and desist letter if you are running a ROM site or selling ROM images illegally. So if I were you, I wouldn't worry.
If you are interested in reading more about the legality of emulation, see this site that I created.

Required Software

The first thing you will need is a file decompression program. If are so new to computers that you don't know what I'm talking about, then you should know that most files that you download are compressed to save space and reduce transfer time. Go to www.winzip.com and download WinZip. This program will decompress files that end in .ZIP. There are other compression formats, but this is the one you will use 99% of the time.
Save yourself a lot of time by downloading all of the 3 essential files listed below. Unzip them and put them in your C:\Windows\ directory.
Cwsdpmi.exe
Dos32
Dos4gw.exe
Then download and install a copy of Direct X from Microsoft.
You may need a BIOS image for the system you want to emulate. These can be just as hard to find as any ROM image that you need. However, try this site. Don't ask me to help you find any BIOS image, or ROM image you need, because I don't know where to find it any more than you do.
There are a few other files you may need. Try looking on my main page near the bottom left side.

Hardware Requirements

In the past (I'm talking 4 to 5 years ago), emulation was slow and buggy. You really needed a decent machine to run an emulator full speed (By decent I mean Pentium 166). However, now days there are emulators that have been optimized for speed, written in assembly, and are almost perfect. You can get away with running an emulator on a 486 if you had to. Many emulators for systems such as NES will run full speed on a Pentium 166, or even slower. But if you are planning on running an emulator for N64, NEO GEO, or any system like that, you should plan on using a computer with at least a 400 MHz processor, 32 MB of RAM, and a decent video card. The better your computer is, the better the emulator will run.

The Emulator

Ok, so now you are finally ready to download the emulator. But which one? Everyone has their favorites. My favorite NES emulator is Nesticle. People now claim that there are better emulators, but I will never use them. Nesticle works great for me. Below I will list my favorite emulators, but you should go to a site like Zophar.net, read their reviews and opinions, and try out the different emulators until you find the one you like. You can fine links and downloads to these on my page. If you don't see the system that you want below, try zophar.net. They have 500 staff members there, so they have plenty of time to waste uploading files for every system.

Nintendo 8-bit	Nesticle
Super Nintendo	ZSNES
Nintendo Game Boy	VGB
Sega Master System	Meka
Sega Genesis	KGEN or Genecyst
Sega Game Gear	Meka
Arcade Games	MAME
Neo Geo	NeoMAME
N64	UltraHLE
TG-16	Magic Engine
Playstation	Bleem
Atari 2600	Stella

The ROMS (Games)

Enough already, you are ready to download the games, right? Well, this is where the difficult part begins. ROMs are illegal to distribute, no two ways about it. So I don't offer ROMs for download on my web site, and I never will. Don't ask me to.
So what should you do? Well, there are quite a few people who, maybe because they are under 21, or because they aren't afraid of being caught, will put ROMs on their web site for you to download. I can't tell you exactly where to find the working sites, with the exact game that you want. This will take your hard work. You can try search engines, "Top Sites", IRC channels, Newsgroups, FTP, etc... I even try to post links to ROM sites on my own site, so just look around. It is even possible to ask someone who has a lot of ROMs to sell/trade you a CD, so you don't have to waste your time. It may be worth your time to ask.
Just don't become a ROM beggar. This is a reason why many of the people who have been in emulation in a long time do not like newbies. Do not ask someone to send you a ROM by e-mail unless they say it is ok (and it's not ok with me). Most people new to emulation may not know better, but now you do, so don't make that mistake, you may regret it. And absolutely, DO NOT ask the author of the emulator to send you a ROM. There have been many emulators that have been cancelled due to jerks begging the emulator authors for ROMs (and don't complain about the emulator either).

Getting Help

So you have downloaded your emulator, ROMs, and you think you have installed all of the necessary files. But the emulator just isn't working, and you would like to kick your monitor, right? What do you do next?
RTFM! Which, if you don't know what that stands for, basically says to read the help file that comes with the emulator. Nearly EVERY emulator comes with a file called readme.txt that will answer every question, and solve every problem you have. I'm just like you, and I hate to look at that file, but do it anyway.
Try a message board. May web sites have a message board where you may ask questions. In fact, many of the emulator authors have web sites where you may post questions on a message board. You can also try my emulation club on yahoo.
As a last resort, try my emulation FAQ, one of the channels on IRC, a newsgroup, email the author of the emulator, another good FAQ, people who run other emulation sites. Beware though, do not act like a jerk on IRC or newsgroups. They have proper etiquette that you must obey, or you will be kicked out and won't get a second chance. And if you want to ask me a question, beware that I really don't try any of the new emulators, and most systems I only try out once, so I don't know the answer to a lot of specific questions.