Motherboard manuals can usually be found online from the company's website. For instance if it's an asus board, the asus website should have a search feature to look up your motherboard model and take you to a product page. From there there should be a downloads area with the manual available.
The pictures aren't really complete, you have to look at the ends of the cables and match them up with the connection pins. The colored wire is the positive cable so if you have two pins for HDD LED on the motherboard, one marked with + and the other with -, the colored wire goes to the + and the white to the -.
If the red/white wires are the hdd led plug, then yes you had them in correct. Red to the + along the left bottom row where it says...