What to see in Guangzhou on a 16 hour layover (7am - 11pm)

Yes, metro shall be the best to way to get into the city for non-Chinese speakers. There are English marks onboard and the broadcasting has English version too. You can take subway line 3 at Airport South station to Jiahewanggang, where transfer to line 2 and get off at Haizhu Plaza (Haizhu Guangchang). Nearby you can take a good sightseeing. Then walk along Yanjiang Road to view the Ppearl River. If you wish, you can also take a cruise for a better visiting. After that, you can walk to Beijing Road, which is one of the most famous pedestrians in the city for dining and shopping. After all these, you can take subway line 2 at Haizhu Plaza to the Memorial Hall of Sun Yat-sen and Yuyxiu Park for a visit.