The web is just full of free and useful tools. For example, you can calculate a person's birthdate from the date of death and age [commonly found on old tombstones] at: birthdate calculator.
Have you found a place but have no clue where it is? Try the Geographic Names Search from USGS.
The largest collection of free family history, family tree and genealogy records in the world. That's what the LDS Web site calls itself. It is constantly growing site without equal.
One of my favorite sites is by Stephen Morse. He has many, many "one step" pages to speed your search of public databases. A good many of them facilitate the search of immigration databases like Castle Garden and Ellis Island as well as manifests from some ports. There are also one step searches for census records and vital records which are online. In addition there are searches specific to Jewish genealogy.
How about the Civil War? [If you call it something grin and bear it - the information is generally filed under Civil War.] If your ancestor served you will want to check the federal government's Soldiers and Sailor System - a searchable database with a microfilm source citation for the information so you can look it up yourself. A state by state list of links [not necessarily free] is another source. Many of the individual state GenWeb sites have their own Civil War information.
Footnote is NOT a free site but it has several free databases of interest, notably the Pennsylvania Archives. They have the Civil War pension files from the National Archives although not in the free databases.
These are just a few of the freebies. Every day it seems there is something new. You can keep up with what's happening in genealogy by reading Dick Eastman's blog. It's free. Eastman has been doing genealogy online for close to 25 years. He'll keep you uptodate and introduce you to sites you never considered.