Formatting Standard Numeric Format Strings
http://msdn.microsoft.com/en-us/library/s8s7t687(VS.80).aspx

Formatting Custom Numeric Format Strings
http://msdn.microsoft.com/en-us/library/0c899ak8.aspx

Formatting Numeric Format Strings (Alignment)
Integer    http://www.csharp-examples.net/string-format-int/
Double    http://www.csharp-examples.net/string-format-double/
DateTime http://www.csharp-examples.net/string-format-datetime/
Align String with Spaces  http://www.csharp-examples.net/align-string-with-spaces/
Indent String with Spaces http://www.csharp-examples.net/indent-string-with-spaces/
IFormatProvider               http://www.csharp-examples.net/iformatprovider-numbers/
Custom IFormatProvider   http://www.csharp-examples.net/custom-iformatprovider/

Character	Description	Examples	Output
C or c	Currency	Console.Write(“{0:C}”, 2.5);	$2.50
		Console.Write(“{0:C}”, -2.5);	($2.50)
D or d	Decimal	Console.Write(“{0:D5}”, 25);	25
E or e	Scientific	Console.Write(“{0:E}”, 250000);	2.50E+05
F or f	Fixed-point	Console.Write(“{0:F2}”, 25);	25
		Console.Write(“{0:F0}”, 25);	25
G or g	General	Console.Write(“{0:G}”, 2.5);	2.5
N or n	Number	Console.Write(“{0:N}”, 2500000);	2,500,000.00
X or x	Hexadecimal	Console.Write(“{0:X}”, 250);	FA
		Console.Write(“{0:X}”, 0xffff);