The round connector is SVID, ignore that. The other two are probably DVI, and I take it your monitor only accepts VGA, the card should have came with a DVI to VGA adapter, if not you can get them for between 1-3 USD, no big deal there.
The power connect sounds like a dual molex to single 6pin connector, if you NEED this, yes you would plug your molex into it, and the 6pin into the graphics card.
However if your PSU has (and it should have if you are using a 4850), 6pin pcie connectors, then use those instead of the adapter.
By the way this is a perfect example of what you need for the adapter and power. http://en.expreview.com/img/2008/07/01/05Gainward4850.jpg