This document is a complete reference of all object types and properties of TypoScript as used in frontend TypoScript templates.
Furthermore, you can find a quick guide to TypoScript templates at TypoScript in 45 Minutes, insights into TYPO3 backend configuration with TypoScript in the TSconfig documentation and explanations of TypoScript syntax in the "TypoScript Syntax" chapter of TYPO3 Explained.