Hi Yogi, and welcome.

I am glad you are considering contributing and I'll try to help as much as possible.
I looked through a good sampling from your link and I think you have some great offerings! Some look ready to go but others are going to need some tweaking to comply.
The big keys to look for are the following:
Size, Alignment, Edges, Cropping, and that they look good on any color background.
Most look like they can be easily adjusted and shouldn't take much work at all to be great additions to our library. The biggest advice I can give it to have a look at the first link in my sig. The links at the bottom of the first post should be very helpful. Unfortunately the link with the picture examples is outdated and deals with SD logos, but the fundamentals presented there hold true on all clear artwork. Just ignore statements about alignment and size.
The video link however is current and shows how we check artwork so you can see what we will be looking for.
Lastly, make sure to really familiarize with the logo rules.
HD Movie Logos (hdmovielogo)
Movie Logos are images of a movie logo/name with a transparent background
Can be used while browsing your media center library as a recognizable navigation item
- Image Size 800 x 310px
- Centered aligned both vertically and horizontally
- 10px gutter, this means the actual image is a maximum of 780px by 290px and any dropshadow/outerglow can go into the gutter, but the image may not
- Try to fill as much width/height as possible
- logos need to be visible on all kinds of backgrounds
- Try to go with the lighter color version of a logo since 90% of skins are dark
- Logo should be authentic to the original logo where possible
- No taglines, actor, director or studio. Just the title of the movie
The only way to prevent denials is to scrutinize each image before uploading as we will do when we moderate it.
As far as how many to upload at once, I would suggest starting with 3-4 just to make sure we are all on the same page. If all goes well I would still recommend keeping the number limited to no more than 10 at a time. Wait for them to be moderated and do it again. This will help the moderators keep their sanity intact.
I hope I haven't scared you off at all. Just trying to prevent what happens all to often. Someone uploads a stockpile of images all at once without really checking them against our rules. When they all get denied it can be a slap in the face, and it's no fun for the moderator either. I'll keep an eye out for your work and am really looking foreword to you joining our community!
Cheers
P.S. Have a look at the other links in my sig as well if you aren't overly familiar with the site.