Glib2d is an excelent 2d graphics library for the PSP by Geecko which can be downloaded here at his git repository. This library allows you to load png images and display them in your homebrew. NOTE: You need to have the PSPSDK installed to make homebrew, to learn how to install it, see Installing PSPSDK We will be working through one of the samples which come packaged with Glib2d called ObjControl. This tutorial will explain every line in the sample after which we will make our own homebew which loads an image and shows it on the screen.
The first thing that you need to do if you haven't done so already is to download Glib2d here