SSRS Report Builder Part 9.6 - Report Variables and Group Variables
SSRS Report Builder Part 9.1 - Aggregate Functions and Scope
SSRS Report Builder Part 6.9 - Matrix Nested Groups
SSRS Report Builder Part 10.4 - Optional Report Parameters
SSRS Report Builder Part 9.7 - The RunningValue Function
SSRS Report Builder Part 10.2 - Query Parameters and Filters
SSRS Report Builder Part 9.9 - The Previous Function
SSRS Report Builder Part 9.2 - Percentage of Group Totals in a Table
SSRS Report Builder Part 9.5 - Highlight Min and Max Values in a Matrix
SSRS Report Builder Part 7.11 - Splitting and Joining Text
SSRS Report Builder Part 7.8 - Concatenating Values
SSRS Report Builder Part 9.8 - Alternating Row Colours in Grouped Tables
SSRS Report Builder Part 6.1 - Grouping Rows in the Query Builder
SSRS Report Builder Part 10.3 - Default Values for Parameters
SSRS Report Builder Part 8.3 - Placeholders
SSRS Report Builder Part 13.1 - Basic Indicators
SSRS Report Builder Part 8.1 - Conditional Formatting in Tables
SSRS Report Builder Part 8.2 - Alternating Colours for Table Detail Rows
MS SSRS tutorial on tablix options, page breaks, repeat headers
MS SSRS tutorial on expressions