General rule is for the base angle the smaller, the grabbier the ski (ie it will start turning with very little initiation on the edge). They higher the angle the more forgiving the ski will be (and it will take a slightly higher edge initiation to start the turn) So .5 or .7 base angle would be for quicker turns like slalom skiing, and 1 degree or higher would many times be for general free skiing and longer initiated turns like GS skiing. Also the .5 base edge can be very hard for entry level, lesser experienced skiers to handle.
Side angle has to many times deal with gripping on ice- ie the higher the angle the better it will carve on icy slopes. A 3 degree would be better than a 1 degree. They are also harder to keep sharpened at the higher degree angle due to the nature of the angle cut. If you are skiing powder then many times you do not want to go as high in the side angle.
Many will go with 1 degree base and 3 degree edge if they are: east coast or icy conditions or a racer. Out in the west, powder skiing and general all mountain they may not have such a high edge angle down to 2 or even maybe a 1 degree.
If you understand the issues and tune your own skis, then you also know that the base angle can usually only be increased, decreasing requires a base stone grind to 0 degrees and then you set it with the proper tools, otherwise the shop sets it on their machine. For others without the tools and no experience- if the factory tune is good, they will keep them at that setting and not change them. The factory angles for various brands can be found on threads here, from the ski manufacturers, or on web sites and catalogs like Tognar which sell tuning gear.
Read through the sticky for basic info and then do some searching on here for edge angle or degrees and read through many past postings on the questions asked- like should I switch from a 2 degree side angle to a 3 degree to get a good understanding of the relationships and issues. Also, again remember that the ski brand can vary with what works best and some do not like the factory tunes at all.