I am a bit new to all this but I think I am going in the right direction...
I have an Inspiron 530 Desktop that I am going to update for my 13 year old nephew as his first computer. The system was purchased back in 2008 and used for 6-7 months and then stuck in a closet - I discovered what true bliss really was once I got my laptop and wireless setup!!! LOL
I want to upgrade the Processor - I was thinking of something from the Intel E7000 Series, such as the Core 2 Duo E7500 or take it all the way and max out with the Intel Core 2 Duo E8600...
1. No. Get whatever ram you can afford. Crucial is most common with oem systems, except dell, which sometimes uses hynix (samsung).
2. For the motherboard, you must check the "cpu support" section for tested cpus, and pay attention to any bios file requirements. You may need to flash the bios using your old cpu. But your dell doesn't list any cpus for updating; they want you to buy a new system. I recommend you post your question on dell's website in one of their forums and see if someone else has tried your new cpu in the same board. Otherwise, you may have to find another dell board that will run it and change the board out unless you have a non dell copy of windows. If you do, then certainly use another board, such as asus.
3. Yes. Oem boards such as dell won't allow you to use faster ram; it will default to the lower speed, so paying extra for faster ram is a waste of money.
4. Yes. 32 bit windows may only list your total ram at about 3.25 gb, which is normal; it has a mathmatical limit on the amount of ram it can use.
5. Never heard of it; but 775 boards have been used so long that some older chipset models won't even post with newer cpus.
6. Yes. But it makes no difference to the board. Go by "cpu support"; some am3 and core2 duos will run with either ddr2 or ddr3, but this is dependent on the motherboard chipset.
7. Depends on the upgrade. For example, don't use a celeron heatsink on a core2 duo; it will run too warm. Temps should range from about 35-65c, depending on your room temp and the load (gaming and prime 95 really increase cpu temps).
8. For overclocking, use the paste. The pad works fine at stock settings.
The 7600 will work fine, but check the dell forum first. Dell bios is very limited; chances are you'll be fine with the p35 chipset on your board, but post the question anyway. I would also check for a used cpu. My local craigslist had a guy selling 3 newer cpus for only $55 the other day: a 7600, i3 540 and i3 530. Less than $20 each.