Ex-dividend dates are very important to dividend investors, since you must purchase a stock prior to its ex-dividend date in order to receive its next upcoming dividend payout. Below are five big-name stocks going ex-dividend for the week of October 22-26, 2012.

PetSmart Inc.(PETM) is set to go ex-dividend on Oct. 24. The pet product retailer offers a wide variety of pet products and services including grooming, training, and boarding. PETM has a current dividend yield of 0.96%. Dividend.com currently rates PETM a "Neutral," with a DARS™ Rating of 3.4 out of 5 stars.

Williams-Sonoma, Inc.(WSM) has a ex-dividend date of Oct. 24. The home goods retailer, specializing in high quality products for the home, has a current dividend yield of 1.86%. Dividend.com currently rates WSM a "Neutral," with a DARS™ Rating of 3.4 out of 5 stars.

Fastenal Company(FAST) is set to go ex-dividend on Oct. 25. This industrial and construction supplier offers products in both wholesale and retail. FAST currently has a dividend yield of 1.92%. Dividend.com currently rates FAST a "Neutral," with a DARS™ Rating of 3.3 out of 5 stars.

HSBC Holdings(HBC) has an ex-dividend date of Oct. 24. This financial services organization, which offers retail banking and wealth management, commercial banking, global banking and markets, and global private banking, has a current dividend yield of 5.7%. Dividend.com currently rates HBC a "Neutral," with a DARS™ Rating of 3.3 out of 5 stars.

The Bank of New York Mellon Corporation(BK) is set to go ex-dividend on Oct. 24. This financial service company, which focuses on investment management and investment services, has a current dividend yield of 2.11%. Dividend.com currently rates BK a "Neutral," with a DARS™ Rating of 3.2 out of 5 stars.

Be sure to visit our complete recommended list of the Best Dividend Stocks, as well as a detailed explanation of our ratings system here.