I'm new and want to customize my PSP

Hi! I have been a modder/homebrewer/ROM player for the DS for quite some time now and never quite had the chance to try out a PSP since I could find a good deal. However, that all changed when someone offered me his phat PSP (3.72) for only $50! Now I have one and am really hoping to get on the scene and start gettign custom firmware, playing ISO/CSOs (what's the difference?) and using homebrew applications, especially one I heard about that supposedly plays N64 games pretty smoothly. Like I said earlier, I have firmware 3.72 and want to get into the PSP scene. Can someone give me detailed (emphasis on detailed) explanations for things I may have to download/do in general? I have received the help of vVCompHelpVv on youtube earlier and although he seems like a smart guy and knows what he's doing, I just don't know enough about the PSP to fully comprehend what he was saying to me. One of the last things I heard about custom firmware that interested me was the use of different themes that are supposed way beyond what .ptf can do (like make different menu types apparently). Can someone explain how to get one of these/make my own? I've made a .ptf theme before but it wouldn't work based on my firmware. Thanks for all your help!

Welcome!
CSOs are just compressed ISOs, they are smaller.
To get on CFW you will need to use the Pandora's Battery and Magic Memory Stick. There are a few tutorials in the tutorial section. You can make them yourself or you can purchase the two on eBay or something.
Ask plenty of questions, we're here to help.

CFW? Serious PSP n00b status here. I have seen tutorials on how to make a Pandora's Battery and MM Stick before, but you always need firmware 1.50, which as far as I've seen, is impossible to get to from 3.72 ATM. Also, are there ISO trimmers? For the DS there is Rominator, which trims off the dummy data in a ROM to make some space (usually about 5-10 MB, but for a PSP ISO it could be more).

PSP ISOs are generally around 400 MB average? They range mainly from 150 MB to 500 MB. But can be over a gig.

CFW - Custom Firmware. You can make the Pandora's Battery and Magic Memory Stick w/o have 1.50 or CFW with this tutorial.
http://pspbrew.com/forum/viewtopic.php?t=11076

I'm just saying if there was a way to trim it, there'd most likely be more to trim I'm guessing, it only trims 5-10 on a DS ROM because the highest I've seen them get is 128 MB. Mario Kart goes from 32 to 24.something . I do have a friend with a PSP that loads ISOs, I'm guessing this means he has a Pandora's Battery and MM stick? It sounded like their was a way to customize another PSP if you already have another customized one. Could this work for me?

Yea.
And you can trim the ISOs with UMDGen v4.
http://rapidshare.com/files/66036319/UMDGen_v4.rar
It also can compress them to CSO.

CSOs play the same as ISOs? Also, is there a guided tutorial you know of for the 2 PSP method? Sorry if I'm annoying you.

Oh, its np. Download this http://www.pspbrew.com/?page=fileInfo&cid=&d=6601
There is a .pdf inside that will tell you everything. Just stick the files on the psp with cfw and install the stuff, then stick the stuff in the psp on official firmware and you are good to go.

I read the Adobe Docs in there and I have absolutely no idea what they meant. My jaw dropped after the main menu pretty much. Also, wondering if CSOs play the same as an ISO. Like if you compress a game ISO.

I've heard that it sometimes makes the game slower, but I haven't experienced it. The pdf is kinda confusing, but your friend ought to know how to make the stuff since he is on CFW already.

Someone else did it for him. He has no idea what he did.

Well, apparently my friend that supposedly had a Pandora Battery, didn't have one. He said that he used a different method before Pandora Batteries were made. So I'm stuck. I saw on dealextreme a good deal, Pandora and 4 GB for $31. However, if the pictures are real, the Battery is fake. It actually say "PANDORA BATTERY" on it. Is this a fake? If not, it may be my best option. I will include a link as long as it is not frowned upon.

Just do what I said

download this http://www.pspbrew.com/?page=fileInfo&cid=&d=6601 and stick the .cso on the psp with cfw.
Download either the 3.70, 3.80, or 3.90 update file, whichever firmware you want to be on. Then rename it to 3XX.PBP
with the XX being 70/80/90 depending on the file you pick.

Make your friend backup all his files on his PC, then do this:

Boot the cso on the psp and once the thing loads, you will see a menu.

Step 1. IPL Menu (Choose 'Install Standard Pandora IPL to Memory Stick)

(Before doing this next step, stick the AC cable in, be sure you are above 75% battery)
Step 2. Battery Menu (Chose 'Backup Battery to ms0:eeprom.bin) then do 'Create Pandora Battery'

Step 3. Firmware Tools (Chose whichever one you want)

Step 4. Utilities & Maintenance Options (Chose the CFW install that resembles the Firmware update you downloaded earlier)

I think you should be good to go now.
I just put this together by looking at the menu just now but I'm pretty sure this should be it.

Now to stick the stuff in your psp:

Hold the L trigger
Insert your Pandora battery
When memory stick light becomes active
release the L trigger

The menu should pop up. Look for the option to install the CFW that you chose. And you're done!

And you should be good to go. You can show the link, I don't think its against the rules, but just get your friend to do this with his psp.

So this will still work even if his battery isn't Pandora? Also, some questions.

1. Will this make his/my battery Pandora?
2. What file do I put the .CSO?
3. Must you have a Pandora Battery and MM Stick to have CFW? Or after you get CFW can you use normal batteries and memory sticks?

Forgot, link is here:

http://www.dealextreme.com/details.dx/sku.12711