I'm looking at this motherboard:
Asus M5A78L-M/USB3
It has AMD 760G /SB710 chip with integrated graphics: Radeon HD 3000
Will it be enough for win7+using office,watching videos,basic games(chess, "spider")?
Simple games require basically no graphic power. It will work fine for them.
According to Ars, AMD's Integrated 3200 is right on the edge of what's required to run all the bells and whistles in Windows 8 Metro - http://arstechnica.com/information-technology/2012/05/recommended-system-requirements-for-windows-8/
Are you sure you don't want to go over the rest of the build? There may be some processor-driven graphic options worth considering instead of this motherboard one.