Hello and welcome to the party.
Although the devs are trying, PSPUAE is not full speed. 90% of the games you would want to play do work at a playable speed. The chaps here have created files called RISS's(
http://pspuae.condor.serverpro3.com/index.php/topic,401.0.html) which makes loading games with the correct settings easier. The game should run at full speed or close enough to make them playable. Read the guide and download the games in the DOWNLOADS section,
http://pspuae.condor.serverpro3.com/index.php?action=tpmod;dl .
For any other answers you might be looking for, read the read-me that either came with the install files or the read-me in the 'documents and faq's' page.
http://pspuae.condor.serverpro3.com/index.php?page=6You should find all your answers there, but feel free to ask if you get stuck.
BTW, PSPUAE is not like your normal console emulator where you only need to select the game you want to play. An Amiga is a complicated computer and so when trying to setup the emulator, you really do need to know what you are doing to get the best out of it. Saying that, PSPUAE does contain some quickstart settings which will allow you to run most games without much tweaking and like I said before, we have created a bunch of RISS's which make the process as simple as load and play. Frameskip is vital to get the games playing at a decent speed.
There are guides everywhere on the net, if you really want to understand amiga emulation, then I suggest you read them. A WinUAE guide will probably explain most of the features of emulating an Amiga that you would need to know about, like CHIPSET, CPU, RAM & KICKSTARTS. I suspect though, that these have already been answered in our documents.
Enjoy!