Comet C/2012 S1 (ISON)
Below is a chart of this comet's positions against the starry background night by night. The map shows a wide view, with the east and south-east points marked. Click on it to get a closer view, with stars marked to magnitude 7. The position of the horizon will change depending on the time and date, but you can use the bright star Spica and the constellation of Corvus as a guide.
A table of positions (known as an ephemeris) for the comet is given here.
The map below gives the positions of ISON after its closest approach to the Sun, should it survive. Click for full-sized view. The horizon is shown for evening viewing, but in the early morning sky before sunrise the horizon will lie apprximately along the left edge of the map.
Comet C/2013 R1 (Lovejoy)
The map below shows its path through November: click for a more detailed view. An ephemeris is available here.