http://www.ncpublicschools.org/accountability/testing/releasedforms

This is an excellent resource. These are actual retired EOG tests from previous years, with at least one released test for each grade level and tested subject.  They are in PDF format and answers are given at the end of each test along with a table that allows you to convert raw scores (number of correct answers) to the scaled scores reported to schools. Check with your child’s teacher to see what levels scale scores correspond to. Remember that Level III is considered at grade level, or passing. The answer table also tells what goal was being tested with each question, so students can see which areas they need to brush up on.

Texas TAKS Released Tests:

http://www.tea.state.tx.us/index3.aspx?id=3839&menu_id=793

Texas is similar to NC in their end-of-grade testing. The TAKS (Texas Assessment of Knowledge and Skills) are scored differently than the NC EOG tests, but the questions are great for practice and include answer keys.

There is also an interactive online version of the tests available at 
http://www.tea.state.tx.us/index3.aspx?id=3264&menu_id=793

Various States Reading Test practice:

http://www.edinformatics.com/testing/read.htm

This site has practice reading tests for NY, MA, and FL (Florida does not test for every grade level).  For some tests the answer key is separate from the test.  Massachusetts also tests writing in their tests. In North Carolina, writing is tested in the 7^th grade and is tested separately from reading.

Math tests from various states:

http://www.edinformatics.com/testing/math.htm 

See above, except this is math.

New York State Math Test:

http://www.edinformatics.com/testing/ny.htm

This site has the NY State Regents released math tests. While the NY state math goals do not correspond exactly to NC goals, they are close and the tests provide good practice. The answer keys are in separate PDF files. This page also has a link for the NY 8^th grade Science test.

California Standards Tests Released Tests:

http://www.cde.ca.gov/ta/tg/sr/css05rtq.asp

This site has released tests for reading and math as well as science. There is no Grade 8 math test listed, but there is an Algebra I test and an Earth Science test.

Miscellaneous Study Sites

There are a number of study sites listed at http://www.randolph.k12.nc.us/schools/serms/Teachers/abrady/Pages/Links.aspx

Some of these are games, some just additional practice.