While researching my book, Cemeteries of the Eastern Sierra, I utilized the California State Library's California History Room in Sacramento. Researching there provided me not only with various books that detailed California's history but also photographs of Inyo and Mono counties, court records, city directories, and newspapers. Other research trips at this facility have provided me with an opportunity to research the Great Register of Voters and county history books.
State libraries and archives may also provide seminars and lectures that can help you hone your genealogical research skills. For example, The Library of Michigan conducted the 2007 Abrams Genealogy Seminar on July 20-21. While the The Arizona State Library has lunchtime family history lessons detailed.
Some library/archive web sites provide online indexes or detailed information on genealogical collections. This provides a way for you to conduct some research without leaving home. One example is that of the Nevada State Libraries link for genealogists. It provides a listing of resources it owns that would be of use to genealogists researching Nevada pioneers. It also provides a surname index for their biographical clipping file. In the case of the Utah State Archives, you can search indexed databases online and digitized death certificates.
You definitely do not have to travel to a state library or archive for it to be of use to you. Most state libraries allow you to e-mail reference questions to them. Some even have research services where they will look up a surname in a resource, make copies and mail them to you for a fee. I have benefited from the Texas State Library and Archives Commission even though I have never visited it personally. Through them I have received the Civil War pension application filled out by my third-great grandmother and received a microfilmed copy of the 1867 voters registration for Austin County via interlibrary loan.
I always recommend that you do your homework before traveling to a research repository. For example, use the online card catalog to determine what you will need to look at once you are there. Often, I find I don't have enough time to do everything I want to do at a library or archive, so it helps to already know what you want to look at. In some cases, what you want to look at may be stored in "closed stacks," meaning that the librarian has to retrieve it for you. This may take some time and/or you may be limited on how many items they will retrieve for you. Make sure you familiarize yourself with the library's web site and find out any rules or restrictions there are on researching collections. Because of storage issues, a collection might be housed at a different location. You will want to know that prior to arriving, since retrieving that collection or book may require more than 24 hours notice. This should be stated in the card catalog.
It is so important to take into consideration any time restrictions you may have. Libraries and archives may also have restrictions involving what can and cannot be photocopied. For example, if you want a copy of a picture, they may require an outside photographer to duplicate the picture for you. This can result in additional costs and time. They may restrict what you can photocopy. In one case I was only allowed 30 copies at a time, which had to be made by the library staff and mailed to me. This meant that I received my copies over a month-long time period because of how many I needed.
Remember that genealogical and historical resources are available in many different places. State libraries and archives provide information not only on the history of a state but individual records of the people who have lived in that state.
Following are the current links to various state libraries and archive web sites:
Alabama Department of Archives and History
Alabama Department of Archives & History
Alaska State Library
http://library.state.ak.us/
Alaska Digital Archives
http://vilda.alaska.edu/index.php
Alaska State Archives
Alaska State Archives
Arizona State Library
Arizona State Library, Archives and Public Records
Arkansas State Library
Arkansas State Library
California State Library
http://www.library.ca.gov/
Colorado State Library
http://www.cde.state.co.us/index_library.htm
Connecticut State Library
Connecticut State Library
Delaware Public Archives
http://archives.delaware.gov/
State Library & Archives of Florida
State Library and Archives of Florida
The Georgia Archives
http://sos.georgia.gov/archives/
Hawaii State Library
http://www.hawaii.gov/hidocs/index.html
Hawaii State Archives
http://www.hawaii.gov/dags/archives
Idaho State Historical Society
Idaho State Historical Society
Illinois State Library
http://www.cyberdriveillinois.com/departments/library/home.html
Indiana State Library
Indiana State Library
State Library of Iowa
http://www.statelibraryofiowa.org/
State Library of Kansas
http://skyways.lib.ks.us/kansas/KSL/
Kentucky Department for Libraries and Archives
http://www.kdla.ky.gov/
State Library of Louisiana
http://www.state.lib.la.us/
Maine State Library
http://www.maine.gov/msl/
Maryland State Archives
http://www.msa.md.gov/
The State Library of Massachusetts
Massachusetts State Library (Boston, MA)
Massachusetts Archives
http://www.sec.state.ma.us/arc/arcidx.htm
The Library of Michigan
http://www.michigan.gov/hal/0,1607,7-160-17445_19270---,00.html
Minnesota State Government Library
http://www.libraries.state.mn.us/index.html
Mississippi Department of Archives and History
Welcome To The Mississippi Department of Archives and History
Missouri State Archives
http://www.sos.mo.gov/archives/
Missouri State Library
http://www.sos.mo.gov/library/
Montana State Library
http://msl.state.mt.us/
Nebraska State Historical Society Library and Archives Division
Nebraska State Historical Society and Archives
Nevada State Library and Archives
http://dmla.clan.lib.nv.us/docs/nsla/
New Hampshire State Library
http://www.nh.gov/nhsl/
New Jersey State Library
http://www.njstatelib.org/
New Mexico State Library
http://www.stlib.state.nm.us/
New York State Library
New York State Library Home Page
New York State Archives
New York State Archives and Records Administration Home Page
State Library of North Carolina
http://statelibrary.dcr.state.nc.us/
North Dakota State Library
http://ndsl.lib.state.nd.us/
State Library of Ohio
http://winslo.state.oh.us/
Oklahoma State Archives
Oklahoma Department of Libraries/State Archive Division
Oregon State Library
http://oregon.gov/OSL/
The Pennsylvania State Archives
http://www.portal.state.pa.us/portal/server.pt?open=512&mode=2&objID=1593&PageID=259971
Rhode Island State Archives
Rhode Island State Archives
Rhode Island State Library
http://www.sec.state.ri.us/library/
South Carolina State Library
http://www.statelibrary.sc.gov/
South Dakota State Library
http://www.sdstatelibrary.com/
Tennessee State Library and Archives
http://www.state.tn.us/tsla/
Texas State Library and Archives Commission
http://www.tsl.state.tx.us/
Utah State Library
http://library.utah.gov/
Utah State Archives
http://historyresearch.utah.gov/
Vermont State Archives
Office of Vermont Secretary of State - Archives
The Library of Virginia
The Library of Virginia
Washington State Library
http://www.secstate.wa.gov/library/?
Washington State Library Blog
http://wastatelib.wordpress.com/
West Virginia Archives and History
http://www.wvculture.org/history/archivesindex.aspx
Wisconsin Historical Society
State Historical Society of Wisconsin
Wyoming State Library
http://www-wsl.state.wy.us/