Usually algebra textbooks provide lots of problems to practice the algebraic concepts and techniques, but some of you may still benefit from resources for free (or mostly so) printable algebra worksheets. Please see the list below, which I've originally compiled for my HomeschoolMath.net site.
Free worksheets for variable expressions
Worksheets for writing simple expressions with variables, when the expressions are given with words. For grades 6-8, pre-algebra, and algebra 1.
Free worksheets for evaluating expressions
Worksheets for evaluating simple expressions with variables, when the value of the variable(s) are given. For grades 6-8, pre-algebra, and algebra 1.
Free worksheets for linear equations
Worksheets for linear equations. Includes one-step, two-step, multi-step equations, variable on both sides, and more. For grades 6-9, pre-algebra, and algebra 1.
Great and free worksheet maker software with nearly 7,000 built-in algebra and geometry questions.
Free Algebra Worksheets from KUTA Software
Free worksheets (PDF) for equations, exponents, inequalities, polynomials, radical & rational expressions and more.
Interactive worksheets that are checked online for most algebra 1 topics.
Math.Com algebra worksheets generator
Generate worksheets for: linear equations, systems of equations, and quadratic equations.
These free worksheets include a few topics such as calculations with polynomials, factoring, and graphing lines.
Algebra Fun Sheets
Worksheets that integrate algebra skills with fun activities including sudoku, word finds, riddles, color patterns, crosswords, games, matching cards, etc. A subscription is required.
About.com Algebra Worksheets
An assorted collection of free algebra worksheets and answers. These pages are not very well organized, but they have lots of worksheets.
Algebra Worksheets from MathWorksheetCenter
Lots of worksheets for over 100 algebra topics. A few are free; most are accessible only by one-year a subscription.
A few fun algebra worksheets
These are for graphing linear equations and linear inequalities.
Online Math Work
Free multiple-choice worksheets for pre-algebra and algebra 1 topics. You can do them online, or copy to a word processor to print.
Lastly... my own algebra worksheet collections, which aren't free but there are many free samples:
Math Mammoth Algebra 1 Worksheets Collection
A two-part collection (A and B) of 137 quality algebra worksheets covering all the topics in a typical algebra 1 curriculum. These worksheets are hand-crafted and contain lots of word problems and other variable problems. Free samples available. $11.50.