Swiss-German is considerably different from German, especially as it happens in regard to those very phrases which a traveler needs: niceties, greetings, asking for stuff, getting directions, etc. One of the key differences to getting by with Swiss German. For example, "Fine, thank you" is "Guet, merci"; with guet being the German word for good/fine, while merci is from the French "thank you". In addition, there are many pronunciation differences which separate Swiss-German from either language. For example, the diphthong in Swiss-German "guet" versus the monophthong in High-German "gut".
Speaking Swiss-German is common for all people living in the Swiss-German part of Switzerland, independent of age or education. For writing, standard German is mostly used, though Swiss-German dialect is particularly popular on informal writing (e.g. in e-mail messages, SMS messages etc.). With the ongoing globalization and immigration, mixing Swiss-German dialects with English (quite often even with pseudo English) or speaking so called "Jugo-Deutsch" (German pronounced as immigrants coming from the former Yugoslavia region tend to pronounce it) has also become trendy for youngsters.
Note that most of the following Swiss-German phrases and words are written as they would be pronounced by people living in the area around Bern, Basel, Zürich. Whilst Bernese dialect is widely understood in the Swiss-German part of Switzerland, it's by no means "official" Swiss-German (despite the fact that Bern is the Swiss capital). There is no standardized Swiss-German ("Schwyzerdüütsch"). Remarkably, the native dialects spoken in the many Swiss-German cantons are clearly distinguishable by locals (i.e. they can tell apart from the dialect in which canton somebody grew up).
a as in master
ä as in can
e as in end
i as in eel
o as in off
ö as in birthday
u as in boot
ü like german i but with rounded lips
Doubled vowels are pronounced longer than single ones.
All diphthongs (two different vowels next to each other in the same syllable) are pronounced with emphasis on the first vowel.
äi, ou, ie, ue, üe are pronounced as written.
eu is pronounced like ä + u
öi is somewhere between o + i and ö + i
b, d, f, g, h, l, m, n, ng, s: same as in English
ch as in loch
gg as in scale
j as in yet
k like gg + ch
p as in spit (not as in pit)
sch as in cash
st, sp usually scht, schp
t as in stack (not as in tack)
v same as f
w as in vane
z as in cats
Like with vowels, double consonants are pronounced longer.