The hardest part of a first GIS project is often not the software but finding trustworthy data. Search results mix official releases, outdated mirrors, and files with unclear licences, and a beginner can lose days downloading data that does not fit together. A short list of reliable, free sources covers most beginner needs: administrative boundaries, elevation, satellite imagery, and street and place data. Bookmark the original portals rather than third-party copies, and check three things on every download: the date, the licence, and the coordinate system.

For country and administrative boundaries, start with national mapping agencies and well-documented open datasets that publish their sources and update dates. OpenStreetMap, accessed through extracts or its editing tools, is the richest free source for roads, buildings, rivers, and points of interest, and its data improves daily through community mapping. When you use OpenStreetMap data, credit the contributors and the Open Database Licence as required, and check that the area you need has actually been mapped in detail; coverage varies between cities and rural areas. For a first project, download a small extract, load it in QGIS, and compare roads and waterways with a satellite base map before running any analysis.

For elevation, look for the national or global DEM that documents its source and accuracy, and keep a note of its resolution for your map credits. For satellite imagery, the Copernicus Data Space Ecosystem for Sentinel-2 and EarthExplorer for Landsat remain the primary free portals, with open aerial imagery available through OpenAerialMap where volunteers have flown. Environmental and climate data, such as gridded rainfall or land-cover classifications, are published by space agencies and research programmes with documentation that explains each variable. Download the documentation alongside the data, because a variable name alone rarely explains its units, processing, or limitations.

Before you build on a dataset, read its licence page: some free data allows any use with attribution, some forbids commercial use, and some requires derivative works to share the same terms. Check the publication or observation date, because a boundary file from a decade ago may miss new districts, and a land-cover map from a dry year may mislead a wet-year comparison. Run basic quality checks in QGIS: count features, look for gaps or overlaps in polygons, and spot-check a few places you know. A dataset that passes those checks is worth more than a larger dataset that has never been inspected.

Create a simple folder structure for every project: raw downloads kept untouched, cleaned copies used for analysis, and final outputs kept separate. Keep a short data log, even as a plain text file, listing each source, its web address, download date, licence, and any cleaning you performed. That log turns a one-off map into repeatable work and makes it easy to update the map when a source releases a new version. Share the log with your map credits, so readers can find the same data and verify your results. Good data habits are quiet, but they are what separate a map that impresses once from a map that can be trusted and updated.

Bookmark the original portals, not random mirrors, and check date, licence, and quality on every download. With boundaries, elevation, imagery, and OpenStreetMap data from reliable free sources, a beginner can build serious maps without spending anything on data at all, and can update those maps confidently whenever a source publishes a newer, better version. Start with one small area, one reliable source at a time, and let your data log grow with each project.