While web browsers work, dedicated apps like Adobe Acrobat or SumatraPDF handle large, image-heavy gaming files much faster.

If you are just starting, these are the core files you need to build a complete library:

If you have $100 to spend on a digital collection, do not just buy random books. Here is the tiered shopping list for .

The humble PDF is becoming a hybrid creature—half e-book, half web app.