Many German sounds will already be familiar to you, but a few require special attention.
Take note of how these letters are pronounced:
ch pronounced from the back of the throat, as in the Scottish loch
r rolled, produced from the back of the throat
s pronounced either s as in see or z as in zoo
sch pronounced sh as in ship
ß a special character that represents a double ss
v pronounced f as in foot
w pronounced v as in van
z/tz pronounced ts as in pets
German vowels can be tricky, with the same vowel having a number of different pronunciations.
Watch out also for these combinations that may look like familiar English sounds, but are pronounced differently in German:
au as the English now
ee as the English lay
ei as the English high
eu as the English boy
ie as the English see
Read this, bearing in mind the tips above, and you will achieve a comprehensible result.
But remember that the transcription can only ever be an approximation and that there is no real substitute for listening to and mimicking native speakers.