About the -ch sound:
We have three different sounds for the "ch".
1) if it is at the beginning of a word and followed by a consonant (like in Chrissi), it is spoken like a k respectively c :
cat,
kitchen,
Christ - all the same sound.
2) following an "i" or "e", like in "ich" or "sich" or "Milch": it's a sound similar to a hissing cat.
3) following an a, u or o, it's a different sound: "Bach", "Buch", "doch". This one sounds a bit as if you had a frog in your throat and try to bring it up (sorry, it's the best comparison I can think of).
For those who want to know it really exaclty, go to the following link. It's an online dictionary. Type one of the example words I used, click go, and then click on the small loudspeaker sign next to the word in the results list. Then you can hear the pronounciation of the word (and the different ch sounds).
http://dict.leo.org/