I definitely know that feeling. You may want to consider using one of the more packaged solutions such as MyHack which provide a way to "ease" into creating a Hackintosh.
Well, I've progressed a bit, with some googling, although I've been unable to start the install.
What I've learnt from other sites:
1- Apple has updated the Mountain Lion installer to 10.8.4. This means that if you bought ML last year but download it again, you now get a complete 10.8.4 installer, without need to download updates. Now I believe I understand why there're different MBR patches for each ML version. I guess I need to use the 10.8.4 MBR patches if I redownload ML today and create the USB from it. Well, I'm just guessing it, although some explanation of this would be greatly welcome.
2- In general it's a pain to update the OSX version on a Hackintosh. So, if you can install 10.8.4 directly, it's better. The bad thing is that 10.8.5 will be released soon and I'm going to install 10.8.4, but, well, 10.8.4 is mature enough IMHO, so I'll keep it forever on this Hackintosh.
3- No idea on how to resize the free space on the usb, though, so I cannot copy the Packages folder into it. Googled this problem, but found no solutions. Disk utility says the usb partition is 8 GB, with 1GB used, and 123MB of free space. Where are the resting 7GB? How can I increase the 123MB? It seems Disk utility can resize partitions, but not this one.
So, well, progressed a bit, but cannot start the install until I find how the USB is created with size enough for the Packages folder.
Anybody successfully created the USB? How did you fit the Packages folder in the 123MB ?
EDIT: Incredible, people seem to just drag the >1GB Packages folder into the usb and it works for them even if there're only 123MB available. I don't know why this works on their machines. On my machine (a MBA with 10.6.8, it won't copy it, showing a "disk full" error). Is it because I'm using 10.6.8? I don't know what to do, I think I'll sleep...