Nothing you really need to mess with before plugging it in. Just have your recorder set to record from the Line Input, plug it in and record. Of course you'll want to set your levels by speaking into the microphone (or whatever else you're using it for) and listening or watching the levels and setting them accordingly. The Tascam is capable of recording in 24bit mode...but if you're just recording lectures than I'd set it to 16bit. You'll have more recording time and you won't really notice a change in the quality.
Yep, but I suggested to him to run in 24bit as long as memory card space is not an issue since you can run the levels more conservatively and boost volume in post.