I have made bark for the last few years - it is so easy and yummy and always impresses since most people see it sold at william sonoma for an arm and a leg! But its SO easy! I made two kinds this year - peppermint and cran-almond.
Melt 1.5 bag of good dark chocolate chips and spread in a 9x13 rimmed baking sheet, lined with wax paper (I also spray it). Chill in fridge till just set.
Melt 1.5 bags of white chocolate chips (if they dont melt well add a touch of shortening to smooth it out). For Peppermint bark, mix in crushed candy canes (4). Spread over the dark chocolate carefully. Top with chunky candy cane pieces, or for the cran-almond, slivered and crunched almonds and chopped dried cranberries and press gently into the chocolate.
Chill in refridgerator until competely hardened (I usually give it at least 24 hours). Pull out and break into pieces. Keeps best chilled.