This page contains a collection of some of the best free Algebra teacher lesson plans from around the web. Great for use by teachers or homeschool parents!
Using Basic Properties to Solve Problems 
Algebra Lesson Plan

"The purpose of this unit is to focus on the Commutative and Associative Properties of Addition, Inverse Properties of Addition and Subtraction, Commutative and Associative Properties of Multiplication; Distributive Property of Multiplication over Addition, Zero Property and the Identity Property for Addition, and the Identity Property for Multiplication. In the content section of the unit under each subtopic will be: explanations about each topic and a set of word problems that illustrates what is meant by each property". This lesson plan includes three separate lesson plans along with objectives, standards, and examples.

Unit Plan: Algebra Basics

Algebra Lesson Plan

The above link takes you to a page containing the 12 instructive lesson plans below. You can also view each lesson individually.

Variables and Patterns  The Pool Border Problem 
Algebra Lesson Plan

"In this lesson students will recognize patterns and represent situations using algebraic notation and variables." In this lesson plan, students work in groups to investigate the number of tiles needed for pools of various sizes and write algebraic expressions. 
Solving Linear Equations Using Manipulatives 
Algebra Lesson Plan

"In this lesson, students use manipulatives to represent visually the steps they take to obtain a solution to an algebraic equation. They develop an understanding of the connections between the solution involving manipulatives and the symbolic solution." 
Teaching Word Problems in Algebra 
Algebra Lesson Plan

This is not a lesson plan, but an article that provides strategies and a number of examples for teaching word problems to algebra students. From the page, "This paper is aimed at the solution of the typical Algebra problem. It is a coach reminding us of the steps we should follow regularly. As one gains skill with a technique many steps are squeezed into a few, one forgets the struggle of learning and rushes off to the solution and then the next question. Word problems are not a topic to be taught at one time and then forgotten. Word problems are a theme of the algebra course. They should be taught throughout the year. They motivate manipulative skills. In summary the paper exists because word problems are seen as important but difficult. The paper is directed to algebra". 
Unit Plan: Algebra in Balance 
Algebra Lesson Plan

In this unit lesson plan "students use a pan balance to study equality, order of operations, numerical and variable expressions, and other key algebraic concepts.". It consists of the following lesson plans:
 Lesson 1  Balancing Shapes  Students will balance shapes to study equality, essential to understanding algebra. Equivalent relationships will be recognized when the pans balance, demonstrating the properties of equality.
 Lesson 2  Balancing Algebraic Understanding  Using a balance in the classroom is a first step to algebraic understanding. Use this pan balance (numbers) applet to practice the order of operations in simplifying numerical expressions and to demonstrate the conventions of using algebraic logic in simplifying expressions.
 Lesson 3  Algebra in Balance  Students use the Balance Pans  Expressions Tool to explore algebraic expressions. They determine if algebraic expressions are equal. They balance pans to solve a system of equations and use graphing to find the solutions to a system of equations.
Lessons include all necessary overheads and worksheets. 