How can I use an external SSD to run my laptop with the current HDD as a backup for media and what not.

Mainly use this laptop for work and it basically stays in one spot 99% of the time. I want to speed it up with an SSD but don't know if my BIOS is compatible, how do I find this out? If I find out that it is capable of doing this is it as easy as installing Windows and a few commonly ran programs onto the drive and changing the boot priority to USB? Will the current HDD still show up with all of my old stuff so I can store things there and use them as well? What would I need to do to make this happen?