Thumbnails and Copyright

[Shudaki Of HalvedStudios]

so i recently discovered i could use custom thumbnails on my videos even though i'm not a partner and do not have adds running on my videos (or at lease i shouldn't have adds.)so i have decided to start making thumbnails but i am unsure as to what i can use for thumbnails and i have several questions about it.

Can i use copy-written images as thumbnails if i add my logo and other additions relevant to my video?
Can i use art found off of google or another sight and if i can do i have to credit the source ?
Can i use screen shots from the game?
Can i use parts of or whole box arts?
Out of those 3 options(original art off a web sight, screen shots, or box art) which one would you recommend?
And any general tips for thumbnails would also be appreciated?

thank you to any one who reply's

 

[SlashGraphics]

#1: Verifying your YouTube account and uploading a video gets you custom thumbnails, not being a YouTube Partner.
#2: You can use websites like Google Images and game screenshots without credit.
#3: Using box arts or other arts that might be copyrighted should be at least given credit in the description.
#4: I would recommend using game screenshots or original art with some bold text, which should fit your gaming videos.