So I've been running a regular SATA HD (BIOS is at ACHI), and just bought a 128GB Samsung 840 Pro. I have a few HD's for storage too. I left everything as it was and installed the SSD in a reg SATA3 port (tried both btw).
if you go into Startup and Recovery under System Properties window (get there by right-clicking Computer in START menu, PROPERTIES, Advanced System Settings) - you can deselect Time to display list of operating systems, or set the time to 2 seconds or what have you
other than that, remove the HDD and reinstall windows fresh on the SSD to make sure the MBR is only on the SSD