I have a 30 minute video that I am preparing for vimeo (or some video sharing site) and it recomends uploading in H.264/AAC and I cant seems to locate the functionality to do such.
H.264 is one variation of the MPEG-4 standard and can be found under the MPEG-4 export. In order for this to work, the program, including the MPEG-4 codec, would have to be fully activated. Load your project, go to the "File" menu to "Export movie" and proceed to "Video as MPEG-4". (ALT+K is the keyboard shortcut you can use.)
In the MPEG-4 export dialog, you can set the file name and so on. Make sure to go into the "Advanced..." settings for the encoder. AAC sound is probably on by default, but you will have to make sure that the video encoder is set to AVC/H.264, rather than just MPEG-4 ISO. Confirm the advanced settings and start the file export. Done!