Hullo, I'm Sarapha! I don't really have anything better to do today, so I'm going to be rating your site! Whooot.
At first glance, your board seems... Well... Bland. I adore the blues, it makes me happy. However, I can't tell at all what the site is about by looking at it. This may sway potential members out of joining, as they probably have a good idea of what they want to be a part of. To fix this, I suggest a heading image that says what the site is (ex. Harry Potter RPG, Twilight, or whatever yours is. In this case, Multi-Media RPG)
Again, the first thing I suggest is creating a header image. Your site looks awfully naked without it. I suggest something blue and white to match the skin. The image you're using as a background was hotlinked, so I strongly suggest making your own, or requesting one, rather than to take a link you found online and stick it there. Since you're going with the theme of something that looks like rain or snow, it should be easy enough to figure a background for it. The menu buttons at the top could also do with some graphicing. Perhaps tiny snowflakes to the far left, then the name of the button to the right, so it looks like this:
The second thing I want to mention is your board colors. The red of the Admin text is very unsightly against the blue background, and it really hurts my eyes to try to look at it. Perhaps go for a duller shade of red? I recommend the color #ff56c7. It's pink, as you have your admin group, but it blends a lot better with the dull blue background. On the same topic, your hovering color for the boards looks very... Blinding, and the color doesn't at all blend well with what you have on the board. I suggest using the color #004bbb for your highlighting, it looks so much better for transitions. In the image below, the color in the center is the board color, the color to the left is what you currently have for your highlighting, and the color to the right is my suggestion.
I also believe the link color should be a bit darker. The dullness of it really contrasts with the board color itself. I believe you should make it the same color as you have for the Windows Background 1" color. This will also help the Windows BG color go more to blend with the colors you already have.
As mentioned above, you really do need better on/off buttons. Even if it's something as simple as a blue square for on and a white square for off.
The chatbox you have should be center aligned. It looks really unbalanced for it to be to the left while the boards and everything else is center-aligned. To do that, go to the very beginning of the Global Footer and type in <center> then at the very end of it, type in </center>
Now, onto the deeper stuff. I'm going to start with your rules and work my way down.
Though typing in short is appropriate for conversation purposes, you don't want to use words like 'wanna' in your rules. You want to be impressionable as an admin, and use proper terms for things. You also want to use proper penmanship, such as using periods at the end of sentences. (note to the first rule).
In your "Character + Roleplaying rules", for number 3, it should be "..until your name has been changed." rather than "....have been changed."
For rule number 5 of "Character + Roleplaying rules", "quantity" has only two 't's', and it should be "I'd rather...", not "I rather...".
The rest of what you have is in desperate need of commas. Some of your rules there, like number 7, were very hard to understand because you had no transitional mark in it.
Now onto the spelling and grammar of your external boards.
In "Forks, Washington" you spelled "people" wrong, and there should be a comma after 'mainly'.
In "Manhattan, New York", the 'y' in 'You' in the beginning of the last sentence should be capitalized.
In "San Fransico, California", you spelled 'San Fransisco' wrong in the title, as well as the rest of the board. Also, there should be a comma after 'San Fransisco', before 'California' in the description.
In "Ads", you spelled 'Advertise' wrong, also with the 'wanna'. The 'W' after the question in "whatever" should be capitalized, as it is coming after a question mark. This sentence makes no sense: "whatever it is you got share it here!" I think you were looking to say, "Whatever it is that you have, share it here!"
It's a nice concept site, but it really really needs work done to it.
Cheers