How to setup a network with 2 ISP??

My company is going to subscribe Broadband from 2 ISPs. I need to draw up a network plan and diagram. How am I going to connect the office network to 2 ISPs at the same time?

What I know is I need 2 router to connect to 2 ISPs. After the routers, what device should I connect in order for the whole network to run without any hiccup? I have a couple of 3COM superstack 3 baseline switches now connecting the LAN.

Or it is not possible at all to connect 2 ISPs at the same time?