35mm would be a wide angle appropriate for group shots and landsacapes. It tends to have a bit of distortion if used too closely. 50 to 55 is standard lens and also useful for small groups of about 2 to 8. 85 to 105 would be your portrait lenses for a single person. The most common macro lenses are 55 and 105. A lot of people go with a 35-85 or 35-105 zoom lens as their base lens. It isn't too large to handle and offers a lot of options. The downside is that getting one with a f setting higher than 4 or 2.8 is difficult and expensive.
i sorta know about that stuff also but 100mm is just too tight for me to use for much aside from portraits alone and i cant seem to find a good 50/55mm in my price range (Christmas present ) that will AF on my camera (not that huge of a deal but enough to bother me) so im sorta leaning to the 32/35mm direction (this one specifically)