It is difficult to overstate the value of maps in genealogy research. In addition to the obvious function of showing you where a particular place of interest is located (often critical in its own right), they can reveal old trade roads that your ancestor may have traveled and transported merchandise over, land features that may have profoundly influenced their lifestyle, or adminsitrative region borders affecting where records of them were kept and in which military units they may have been drafted.

For Galicia and the former Austrian Empire, I highly recommend looking at the 3rd Austrian Military Map (c. 1910).

Since there is no place index, the only way to find a location is to find the major city on the overall map that it is closest to and then estimate its direction and distance from it, according to the map scale. This should help you determine which submap to search in. The primary value of this map is that it includes small villages that are often not included in other maps and displays them with their original Polish spellings, those found in the records of the time. Since the western half of former Galicia is now located in Ukraine, modern maps will typically have the place names in Cyrillic, or an English transliteration, which may not be recognized.

For Germany, I recommed the Karte des Deutschen Reiches (c. 1893), with a scale of 1:100,000. This map also shows a considerable degree of detail, including many small towns and villages.

And for the former Russian Empire, please see Генеральный Штаб Рабоче-Крестьянской Армии (1:100,000) or, for more detail, Новая Топографическая Карта Западной России (1:84,000, 1880-ca1935).

A great all-encompassing map comprising large swaths of each of these areas at a scale of 1:300,000 is the √úbersichtskarte von Mitteleuropa (note: this map is quite large and may take some time to load).