Welcome to the Bulbagarden Archives, MAGNEDETH! As a new user, you probably won't bother reading this and will make numerous poor edits and get yelled at before realizing anything, so, there isn't really a point to this. Basically, it lets me feel like I'm actually contributing to the site. Enjoy!
The Manual of Style, or MoS, is one of those things we stole from Wikipedia. No one has any idea what it's for, but it makes us look more professional. Why bother reading it though, when you're obviously not going to follow it?
Tagging images with correct licenses and categories is a bit of a drag. Try as you might, but if at first you don't succeed, you're gonna get hammered by the admins. And you won't improve. Ever.
There is a checklist you should read when you upload. All our users lead by example, though, which means you should disregard the checklist entirely. Why should you put in any effort here?
Tagging and categorizing images is important for organization, but lame in principle. Just mass upload everything using 500 tabs in Firefox. Then do 500 more in Safari.
Duplicate images suck. Then again, so do you, and you're still here.
If adding a licensing tag to anime or game screenshots, please avoid just choosing "Screenshot". While this is correct (hey, we all want to do things right!), the admins are pedantic and lazy and don't want to spend any of their valuable time cleaning up after you. Didn't I already warn you to not make them mad?
Does your image have a purpose? If the image has more purpose to be here than you do, it's probably already uploaded. See "duplicates".
Personal images totally rock! We all like personal images, and the more, the merrier. Don't get too personal though - if anyone sees Kogoro's face the world will actually implode. Seriously. You have been warned.
When you name your images, do it in a way that you'll remember the image. If you're a math geek, then naming all your images after the largest known prime numbers would be a sensible option.
Due to Bulbapedia's bitchy staff members, most of the images you upload aren't going to get used. They will suck. They will pale in comparison to what is already there. They will make your life not worth living. Long story short, you fail at wiki.