Now you said it's best, however, if you don't have a mixer is it still possible?
It might be, but if you think that setting it up with a mixer might be difficult, I can assure you that without one it's going to be a whole load harder, especially if you have to use an internal sound device. And no I haven't tried - nor am I likely to.
Also, the PDF is great. If I get a mixer, Are there directions for after you set that up and you need help setting up the interface?
No, because I haven't rewritten it yet! (as mentioned on the other thread).
If you are serious about doing this, a small mixer is a very good idea anyway, and they really don't cost that much nowadays. I haven't tried it, but I think that it should be relatively easy to set this up with one of the mixers that also contains an audio interface (so you just have to connect it via a USB cable). I will look into that. The version in the .pdf works with any mixer, although it needs unimpeded line in/line connections on your computer. Most of them can just about manage this, but some manufacturers still make this difficult.