In addition to free indexes and records, subscription sites may offer complimentary family history tools, though subscriptions may be required to get the most out of them:
Access to online catalogs: Through AmericanAncestors, you can access the New England Historic Genealogical Society’s online catalog of its library collections. At Ancestry.com, you can search a catalog of NARA collections that are now available on that site.
Online education: Learn from online how-to articles and resources. Archives.com’s Expert Series, though no longer adding new content, has dozens of how-to articles. Ancestry.com’s Learning Center offers free tips and advice. You’ll find free Research Guides on topics such as major US immigration ports, German civil registrations, Ancestry.com search strategies and more.
The site has two more key resources on its wiki: The Source: A Guidebook to American Genealogy (3rd edition), edited by Loretto Dennis Szucs and Sandra Hargraves Luebking, and Red Book: American State, County and Town Sources (3rd edition), edited by Alice Eichholz.
Teasers to related records: As you search free indexes at Ancestry.com, MyHeritage and other websites, additional databases with related content will be suggested along with your results (often on the right side of the web page). Subscriptions are required to fully access these.
Tree-building tools: Build your family tree for free online at Ancestry.com, Findmypast or MyHeritage. The latter also offers a free downloadable version of its Family Tree Builder software. Use it to keep your master family tree on your own computer and sync it regularly to your online tree.
From the March/April 2016 Family Tree Magazine