So you want to upload PS2 games, but you're not sure how?
Well first, follow http://www.ps2iso.net/index.php?topic=343.0 to backup your game ISO. If you already have an ISO, or if you downloaded it, then you don't need to follow it since you already have the ISO.
Now, the splitting. I use WinRar to split it since I have WinRar, and it's in some ways, simpler for downloaders as RAR split files are the most common.
First, download WinRar. You can get it from anywhere, there's a copy in the PC Apps on this site.
Open the folder that your ISO is in. Right click the ISO, WinRar, add to archive.

Name it whatever you want. Set the compression method to whatever. I set it to ultra to save a couple of meg, to be honest, my PC compresses those extra couple of mbs quicker then my internet connection can upload it so it's better for me. But whatever. The important bit is split to volumes at the bottom. You set the part size here.
The part size is generally the file size limit of your file hoster, e.g. MU allows 1gb per file now, RS allows 200mb per file etc.
Set a different location in the archive name box if you want. If you want it in the same folder as the ISO, then just type the rar name you want. If you want it in a different location, then type the full address and file name. Examples: Code:
Final Fantasy X-2 PAL.rar
ffx2.rar
blabla.rar
C:\temp\ffx2.rar
C:\Users\Bobo\Documents\sfaha.rar

If you want to set a password then click the advanced tab and "set password". Type whatever in the password box, and type the same in the second box. I'd recommending ticking encrypt file names as it doesn't let people who don't have a password see what's in the rar file, so they don't know it's an ISO or anything in the first place. Click OK.

To speed it up a bit, uncheck the first box in the "time" tab.

Click OK and wait years.
Then, upload the individual parts on a file hosting site. I'd recommend you create an account since you can manage them easily, if you ever need to. Post the game here or wherever, and post all the individual part links. Post a boxart if you want. And you're done!
Thanks for uploading!