Use LaTeX for typing up the notes. The notes should be polished and comprehensive (for example, they should include references, figures, etc). Send me an email to schedule the dates when you'd like to scribe. The notes are due one week after you scribed (in .tex and .pdf format).
Pick a relatively recent paper from a theoretical CS conference (FOCS, STOC, SODA, CCC, APPROX-RANDOM, ICALP, ICS). Some good places to start from are the Electronic colloquim on computational complexity and the Algorithms and data structures arxiv. Also, check the course website for some suggested papers.
Meet with me twice before the actual scheduled presentation. The first meeting should be scheduled early in the semester so we can discuss your topic selection. Schedule the 2nd meeting one week before your presentation. Before the meeting, email me a good draft of the notes for the material that you'll be talking about. The final draft is due the day of your presentation.