Most TVs will just detect the computer and automatically display the picture. If you're having issues with it the most common remedy is switch the TV on first and then the PC.
If you want to use the PC while your hubby is watching stuff on the TV screen you'll need to use the extend desktop option from your graphics settings (right click on the desktop > properties etc etc etc or go to control panel and access graphics settings there).
The default option is usually 'clone' though, which means that you'll both see the same thing on the PC screen and the TV screen. So you'll need to go into options and change it to extend desktop which will in effect 'stretch' the screen.
You don't say if you're using onboard graphics or a dedicated card. As far as I know (and I'm prepared for someone to chip in and prove me wrong on this one because I could very well be) but only AMD graphics cards also output sound over HDMI, also if it's an older card (dual DVI with an HDMI adapter) the sound will only output over port 1
So whatever graphics you're using you might want to check that it's able to output sound over HDMI otherwise you're going to have run your computer speakers to your TV for sound.