SmugMug allow its users to upload unlimited number of JPEG, PNG and GIF files. However, in order to upload any other file type, you'll have to use SmugVault. SmugVault is an added service to your current SmugMug account. With this you'll be able to upload RAW, TIFF, and PSD files to your SmugMug account.
As far as the file size is concerned, SmugMug allows you to upload a maximum file of 50 megabytes and 100 megapixels. To upload files bigger than this, you'll have to do it through SmugVault.
You can now install PicBackMan's SmugMug uploader for Mac from the website and start backing up photos and videos.