This is a simple stored procedure that you can use to generate a random string. You can use it as a random password generator and for other purposes. It is very simple so I won't bore you with unnecessary explanations but if you do happen to have any questions feel free to post them here.
CREATE PROCEDURE [dbo].[usp_GenerateRandomString]
@sLength tinyint = 10,
@randomString varchar(50) OUTPUT
SET NOCOUNT ON
DECLARE @counter tinyint
DECLARE @nextChar char(1)
SET @counter = 1
SET @randomString = ''
WHILE @counter <= @sLength
SELECT @nextChar = CHAR(ROUND(RAND() * 93 + 33, 0))
IF ASCII(@nextChar) not in (34, 39, 40, 41, 44, 46, 96, 58, 59)
SELECT @randomString = @randomString + @nextChar
SET @counter = @counter + 1
There are of course other ways to accomplish this – a very simple one would be to use newid() and grab whatever number of characters you need from it.