Just Devhook? OK. Here's how to do it -
1) Download this -
RapidShare: 1-Click Webhosting
2) Connect youe PSP to your PC via USB, and open the file. It's an installer, and will take you though half the process of installing Devhook.
3) Click Next until you get to a part where it asks you for your PSP's root. Find out which drive letter your PSP has been assigned, clear the box, then put it in, followed by a colon and a backslash (so it would turn out like this - M:\ )
4) Finish the installation by clicking Next until it is installing the files. It may appear to freeze when it's copying a file, but just leave it - one of the files it needs to install is over 20MB, so it might take a while to finish.
5) Back to your PSP. In the Game section of it, go into the Memory Stick submenu, and run the application called "Devhook Firmware Installer". Follow its instructions.
6) Devhook is now installed on your PSP! Here's how to use it -
Using Devhook
1) Run Devhook from the Game - Memory Stick part of your PSP's menu.
2) Remember that we use O, not X to select things in Devhook. Go into the menu called FIRMWARE, and select 3.11.
3) Go into the UMD SELECT menu. Select UMD Disk to use a UMD.
4) Select START DEVHOOK.
5) Some lines of text will scroll down your PSP's screen, then your PSP will appear to reboot into firmware 3.11. Press HOME to close the translucent menu that comes up, then you'll be in 3.11! You can do things like browse the internet and look at RSS feeds - basically everything 3.11 can do - from here. To get back to 1.50, simply restart your PSP.
Hope this helped,
Dork