I listen often to Kim Komando's talk show and found today's Tip of the Day newsletter offered a lot of practical advice on buying a new PC, as well as an easy-to-understand overview of the latest micro-processor developments.
http://www.komando.com/
http://www.komando.com/tips/categories.aspx?cat=43
Picking a microprocessor
It's time to move up from my old Intel Pentium 4, 3GHz system. Where can I learn about what's out there? Dual Core? Dual Quad? I need a simple explanation about these processors.
A lot has happened since your microprocessor was introduced. The 3GHz Pentium 4 goes back about five years. That qualifies as an eon in computers.
For most people, that old Pentium 4 would still be adequate. Today's cutting edge chips are running far in front of consumer software. So, unless you're editing lots of video or playing the most demanding games, you don't need to worry about the chip. Today's chips are more advanced than your Pentium. As you point out, they have multiple cores. They are also 64-bit chips, while yours is 32-bit. The architecture of these things is just brilliant. But most of it is going unused.
Let's start with the cores, since you mentioned them. Each core is its own little processor. Both Intel and AMD are producing multi-core chips. The most advanced Intel chips have four cores. AMD had the chip lead at one time. But it struggled with its quad core chips. It did finally get them out, well after Intel. Quad-core chips work well on servers. But they are overkill in the consumer space. A quad core gives you one thing—bragging rights.
Windows is capable of running on multiple cores. So it can take advantage of these advances. But few consumer programs use more than one core. In fact, porting consumer programs to multiple cores is a huge concern. The same type of thing applies to 64-bit chips. This number refers to the amount of data a core can crunch at once. AMD and Intel chips now are 64-bit. That's pretty meaningless, though. Practically everything else is 32-bit.
True, you can get a 64-bit version of Windows Vista. But I don't recommend that. You would probably discover that drivers are hard to find. That would mean that certain peripherals couldn't be used. You could probably get by with Intel's Celeron, or AMD's Sempron. Both are budget microprocessors. But you can't be sure of what the future will bring. So I would go with an Intel Core 2 Duo or AMD Athlon X2. If future programs use dual-core technology, you'll be ready. You might see high-end computers with Intel Extreme or AMD Phenom chips. Those are very powerful. They should work well in gaming and video-editing situations. Otherwise, you can't use the power.
I assume you'll be buying Windows Vista. You will see one of four versions. I have a chart that explains them. There is a fifth version—Enterprise. You won't see that in stores. Vista is more capable than its predecessor, XP. Consequently, its video requirements are pretty stiff. Get a minimum of 128 megabytes of video RAM. Go for 256MB, if you have room in your budget. I prefer a separate video card. But integrated graphics will also work. I have a tip that explains this further. Don't overload your system with random access memory. I recommend 2 gigabytes. If you need more, go up to 3GB. Over that, and you're probably just throwing your money away.