Spin It Again does not have the option to load more than one audio file. If you're recording the audio, pause Spin It Again while you turn the album over. Otherwise, you could join the audio files together in another program before you load them into Spin It Again.
In regard to your second question, what are you using to view the files? If you're using a program like iTunes or something, you could create a playlist.
You can see how long your recording is in Spin It Again, but there's no time signature guide.