Easy, type the word link. Then highlight it, go to the link button which will be highlighted also, paste or type in your link. Done.
Example in use....
Hey everyone, click on this link to see some really awesome artwork.
You get the url (link) by going to your skin, in the gallery, and copying/pasting the url into the link box as I stated above.
As far as before they're moderated, you can't know. It is against WC policy to link to skins that are in moderation....this kinda defeats the purpose of moderation.