How do you know if the Mobo can use dual core processors or more? Can you put them in any mobo, or what specs do i need to look for on a Mobo to know what i can put in it.
Depends on the motherboard, and depends on which dual-core CPU. Certain chipsets support them and certain do not. Also, each motherboard has its own list of supported CPUs, which you can usually obtain from somewhere on the manufacturer's website.
If you have a question pertaining to a specific CPU or board, feel free to ask it and we'll probably be able to help you out.