Link list

Here is a list that sums up useful tools and software or to dig further:

Light pollution map: www.darksky.ch

Planetarium software
stellarium (free)
cartes du ciel (free)
tonightssky.com (what is visible tonight at your location,  Messier objects etc)
google sky app (free)
stellarium app (not free)

Alignment:
polarfinder app
http://www.takahashi-europe.com/support/softwares/polarisfinder/polarisfinder-1.5-en.htm
http://myastroimages.com/Polar_FinderScope_by_Jason_Dale/

Image manipulation:
imagesplus
photoshop
adobe lightroom
startools
pixinsight
gimp (free)
iris (free)
SIPS (on laptop)

Stacking images:
deepsky stacker (free)
iris (free)