KPMG Tax Rates Online: Time series data by country from 2010 - present for Corporate tax rates, Indirect tax rates, Individual income tax rates, Employer Social security rates, and Employee Social security rates.

OECD iLibrary (Organization for Economic Development) 

1. In the OECD iLibrary database, click the menu to Browse by Theme then click Taxation.
2. On the left-hand menu under Statistics, click Databases then click OECD Tax Statistics.
3. Click to view the range of data including Personal Income Tax and Corporate Income Tax.

Tax Foundation: Historical country data and analysis.

• Corporate Tax Rates around the World
• Global Tax Maps