Code Guidelines

Naming conventions

variable and method names must be self-explanatory
variable names must be in CamelCase
class names start with capital letters
variables start with small letters
constants should start with "k"

Complexity Limits

lines per method <=100
method complexity: number of control elements (if/case/foreach/...)) <=10
number of parameters per methods <= 7
number of lines per source files <= 1000

General

write unit tests where useful and possible, at least for each fix
no magic numbers (define global constants in one place instead)
if statement must contain brackets at beginning of line
commented code should be avoided
lists should be used instead of arrays
only use comment per line (//, #), no block comments
continue style of existing code in source file
all recursion needs to be limited (default max. value: 100) to avoid stack overflows

C# specific

avoid null references
methods should be preceded with standard comment header (///)