If you are a complete newbie, and you want to build a low end to moderate system, you might as well stick to Dell. Their prices are fair for what they offer, and their quality is decent - not to mention they bundle in software.
If you are serious about building a computer, then there's a hell of a lot you should know about.
The essentials:
Case: Unless you want to do something special, stick to mid-tower ATX cases with no less than a 350W PSU. I prefer the ANTEC brand PSUs. If you buy a generic PSU, you'll be buying a new one in less than a year.
Processor: AMD, Intel, - whatever. Get whatever is tailored most to your needs / budget. To answer the preliminary question: No, 64 bit processing will not give you any major benefits since almost all software for regular home users is 32 bit anyhow - and it wont be changing all that soon. (That's not to say 64 bit processing is useless - just that it might be a bit over budget for you). As you mentioned, get RETAIL, unless you plan on buying the heatsink yourself. Retail also usually includes a better warranty.
Motherboard: Make sure it matches your processor and case size. Try not to accidentally buy a Micro-ATX form factor motherboard for a ATX case. The choice of the chipset may make a difference for your use, but for the everyday user, it probably doesn't make a difference. Good motherboards usually include a NIC (network interface) and sound built-in - so you wont need to spend money on a separate sound card or NIC, unless you want to setup wireless. I recommend ASUS or MSI. SOYO, though not the greatest, isn't horrible either. You can buy a newer motherboard that supports PCI Express if you want - though it's still a relatively new technology - and unless you are building a top of the line system, it isn't really necessary. (If you want a true gaming system, check out the new nForce 4 boards.)
RAM: Get whatever your motherboard supports. If you are buying dual-channel RAM, then you will need to get two sticks of the same size (ie: 2x256 or 2x512). To run dual-channel RAM, your motherboard needs to support it.
Video Card: ATI, Nvidia, etc. Those two are probably what you will want to stick with since they have the best driver support for Windows-based systems (and Nvidia for Linux -
although ATI is releasing new Linux drivers soon). Those two main brands are quite comparable in performance, so ultimately it's your choice - much like the processors. Also, depending on the motherboard, watch out to see if you're buying AGP or PCI Express cards.
Sound Card: On-board sound should suffice. If not, check out a Creative Audigy 2 ZS (even though Creative are bastards) or a Turtle Beach card.
Hard Drive: Capacity is up to you. I really don't recommend anything lower than 60 GB. There are a few notes you should look out for. The first is the buffer size. Make sure you buy a hard drive with an 8 MB buffer - 2 MB just doesn't cut it anymore. Now, once again, depending on your motherboard, you have the option between SATA and IDE connections. To clarify: All motherboards support IDE, and most newer ones include SATA connections as well - the choice of what kind to buy is up to you as long as your motherboard has support for both. You wont see any significant gains from using one over the other, and you can use both a SATA and IDE drive simultaneously if you want. As far as brands go, I prefer Western Digital - as do most people I talk to. However, there are those who have had WD drives crap out on them and they prefer either Maxtor or Seagate. If you are a pro, you can look into setting up RAID - but since you say you're new at this, forget I mentioned it.
Optical Drive: Depends on your needs. It's nice to have a DVD burner, and since prices have dropped over the past year, you can get a good one for cheap. Buy an NEC 3500 for just $60 at Newegg. If you don't want to spend that much, then you can get a DVD drive for $25 or a CD-RW for around the same price.
Monitor: CRT is still cheap and high quality. LCD is expensive and high quality (depending on which on you buy). If you want to purchase quality stuff, buy a good LCD screen with a DVI connection and a 16ms or less response time.
Speakers: Your call. Though I can give input on brands if you would like - depending on the setup you want (ie: 2.1, 5.1, etc.)
Mouse & Keyboard: Your call.
Printer: Another story.
Floppy Drive: I still recommend people have these - but there are those new elitists that insist the floppy is now useless and will use USB Flash cards. Psh.
Software: Microsoft Windows XP Home for a novice who doesn't want to do anything but use the computer for playing games, browse the net, and write emails. XP Pro for someone who wants a bit more networking capabilties, but not much else. Any Linux Distro for someone that doesn't want to pay for an OS or wants much more customizability, and sometimes more functionality.
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I highly recommend buying most of your items from
http://www.newegg.com if you live in the States. They have great prices, great support, and use FedEX shipping that normally ships within 3 days. When you buy at places like BestBuy, CompUSA, Fry's Electronics, etc - you might get a deal, and you might get screwed. They like to put a good markup on certain items, so you need to be careful when shopping at retailers like that.
Now, a few key notes:
- When you are putting your motherboard into your case, make sure to properly ground it. This means, you need to use those little plastic washers between all the screws but one. Some people don't bother to do this and it doesn't make a difference. Some people don't bother to do this and their computers don't work and they can't for the love of them figure out why.
- When you setup your hard drive, you will need to partition it. Windows XP (assuming you choose this OS) will give you the option to do that during setup. Most Linux distros do as well. I recommend that you create at least two partitions on one hard drive. Why? Well if you want to backup your files so you can easily format your computer, it makes it easier than just burning everything onto CDs or uploading to another computer. Also you can organize your files in easier ways.
- Do not underestimate the importance of your power supply.
- Follow the included manuals and don't try and force anything into place and you should be fine.
I'm sure there's a few things I'm forgetting. I'll add once I remember or if anyone throws them in. Good luck.
