It is best to reinistall windows when switching to SSD. Many have just cloned their drives and it has worked.
I would suggest Samsung because first off they are great drives, and secondly they come with a drive copy tool.
If this is a desktop you will just plug the drive into one of the sata ports on the motherboard.
If this is a laptop you would need a usb to sata converter to clone the drive. If your laptop has USB 3.0 (the usb port will be blue) then get one that is usb 3.0 as it will be faster.
Either way you should switch the sata type in the bios to AHCI.
You can find instructions on how to do this in your motherboard manual.
If you going to clone your existing drive do the following steps:
Perform the registry change at this address:
http://support.microsoft.com/kb/922976
Now go into bios and change your sata type to AHCI
Now you should be able to boot back into windows.
Once windows boots for you again, power off the computer
Plug the ssd drive in (sata port if desktop, use usb adapter if laptop) with the original hard drive in place, power back on and boot into windows.
Boot back into widows and run the Samsung Data Migration software that came with the SSD.
Once complete remove the old hard drive, plug the ssd drive into its sata port
If desktop then you may have to go into bios and make sure it is set as first boot device
Now boot up with your much faster SSD drive.
You can now plug the old hard drive into your computer, format it and use it as a second hard drive; or you could just set it aside as a backup.
If doing a full reinstall of windows:
If computer is a laptop Go to motherboard or computer makers website and download the AHCI/SATA driver for it.
While at the vendor's driver page download the lan, chipset, audio, vga/video driver and if it has it the wifi, Bluetooth, usb 3.0, sd card drivers.
If there is no driver on the site then the generic windows driver is fine and you can skip the step latter about loading additional drivers.
Copy drivers to a usb flash drive.
Remove old hard drive.
Install SSD drive.
Go into bios and set to AHCI under sata type
Begin windows installation
In the section where it asks you to select the hard disk to install windows to, there is a button that says load drivers, press it and navigate to the flash drive you saved the drivers on and select the AHCI driver.
You can now install windows.
Once finished installing windows you will need to install the rest of the drivers you downloaded