Tobias Mayer (1723-1762) is often called by the name of Johann Tobias. That is a mistake. Tobias had only that single first name during his lifetime. Johann Tobias Mayer (1752-1830) is his eldest son. Both men were once professor in Göttingen; and both men published on mathematics and geography. Johann Tobias probably pirated some of the unpublished manuscripts of his father and published them under his own name. But that should be no excuse to name the father after the son. Many libraries propagate the mistake in their indexes.
The history of mathematics website of Saint Andrews has its own peculiar way of mixing things up. On the page with the biography of Tobias he is called Johann Tobias, although the html address of that page has it right. On the page is a thumbnail with the portrait of Johann Tobias the son. When you click on it you get two portraits: the one to the right is right, but the one on the left is again the son Johann Tobias.
The mistake of St. Andrews is echoed in Woodville and Montpellier.
Fortunately, the reprinters of Johann Tobias Mayer's works know their business: they associate the right names and portraits with the right persons.
Several biographies are on the web, for example here, but I have not checked their quality. Manfred Holl maintains a website dedicated to the history of astronomy, with a biography of Mayer. There is a school named after Mayer, where a biography was prepared.
The story of the longitude prize is told by, among others, Making the modern World and Tue Kell Nielsen.
Some of Mayer's detailed drawings of the lunar surface are documented in the Linda Hall Library of Science, Engineering & Technology at p. 12, p. 13, and p. 25. Some mooncraters (including one named after Mayer) are illustrated on a Nürnberg site.
Mayer's map of the lunar eclipse of 8/9 August 1748 is scanned by the French national library. Speaking of eclipses, the Eidgenössische Technische Hochschule Zürich has a particularly nice website with historical material.
Mayer's Abhandlung über die Umwältzung des Monds um seine Axe und die scheinbare Bewegung der Mondsflecken published in the Kosmographische Nachrichten und Sammlungen auf das Jahr 1748 is important in the history of statistics because it contains the first successful application of equations of condition, a method to solve an overdetermined system of equations. This method was in use for about half a century until it was replaced by the method of least squares. The Nachrichten were intended as a series, but only this single volume has ever been published.
An exhibition was organised in the Paulinerkirche next to the old building of the Niedersächische Staats- und Universitäts Bibliothek SUB; the site has many links and abstracts and also a timeline. The SUB library has most of the Mayer manuscripts, by the way.
Axel Wittmann has used Mayer's observations to investigate if there is any change in the apparent solar diameter over the last 250 years.
Other subjects that had Mayer's interest include earthquakes and colour mixing (see also these stories in English or Deutsch, and this nice illustration).
Travels through Arabia and Other Countries in the East