Below are some of the comets to keep a watch for in 2017 as they should be observable with small scopes and even binoculars.
Currently observable low in the evening at around magnitude 8 and will continue to brighten to magnitude 7 in January and then fade rapidly, including a approach to within 0.08AU of Earth on February 11th, as well as passing within a few degrees of globular cluster M3 shortly after.
Photo from January 6th.
C/2016 U1 ( NEOWISE )
Currently observable at magnitude 9 and predicted to brighten to magnitude 7 in mid January. Discovered on October 21, 2016. Not visible in the southern hemisphere.
C/2015 V2 ( Johnson )
Faint at magnitude 12, and will continue to brighten until mid 2017, with good chances of observation.
C/2015 ER61 ( PanSTARRS )
Should brighten to magnitude 7 spring of 2017, unfortunately not very visible to the northern latitudes. However it will cross many NGC and Messier objects throughout the first half of the year.
Expected to brighten to magnitude 6-7 around at the start of March, overall visible for about 45 days. For those in the northern hemisphere, best observations will be the end of February.