SQL Logins

In actual server you can run:
CREATE PROCEDURE sp_help_revlogin @login_name sysname = NULL AS
DECLARE @name sysname
DECLARE @xstatus int
DECLARE @binpwd varbinary (256)
DECLARE @txtpwd sysname
DECLARE @tmpstr varchar (256)
DECLARE @SID_varbinary varbinary(85)
DECLARE @SID_string varchar(256)

IF (@login_name IS NULL)
DECLARE login_curs CURSOR FOR
SELECT sid, name, xstatus, password FROM master..sysxlogins
WHERE srvid IS NULL AND name <> 'sa'
ELSE
DECLARE login_curs CURSOR FOR
SELECT sid, name, xstatus, password FROM master..sysxlogins
WHERE srvid IS NULL AND name = @login_name
OPEN login_curs
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @xstatus, @binpwd
IF (@@fetch_status = -1)
BEGIN
PRINT 'No login(s) found.'
CLOSE login_curs
DEALLOCATE login_curs
RETURN -1
END
SET @tmpstr = '/* sp_help_revlogin script '
PRINT @tmpstr
SET @tmpstr = '** Generated '
+ CONVERT (varchar, GETDATE()) + ' on ' + @@SERVERNAME + ' */'
PRINT @tmpstr
PRINT ''
PRINT 'DECLARE @pwd sysname'
WHILE (@@fetch_status <> -1)
BEGIN
IF (@@fetch_status <> -2)
BEGIN
PRINT ''
SET @tmpstr = '-- Login: ' + @name
PRINT @tmpstr
IF (@xstatus & 4) = 4
BEGIN -- NT authenticated account/group
IF (@xstatus & 1) = 1
BEGIN -- NT login is denied access
SET @tmpstr = 'EXEC master..sp_denylogin ''' + @name + ''''
PRINT @tmpstr
END
ELSE BEGIN -- NT login has access
SET @tmpstr = 'EXEC master..sp_grantlogin ''' + @name + ''''
PRINT @tmpstr
END
END
ELSE BEGIN -- SQL Server authentication
IF (@binpwd IS NOT NULL)
BEGIN -- Non-null password
EXEC sp_hexadecimal @binpwd, @txtpwd OUT
IF (@xstatus & 2048) = 2048
SET @tmpstr = 'SET @pwd = CONVERT (varchar(256), ' + @txtpwd + ')'
ELSE
SET @tmpstr = 'SET @pwd = CONVERT (varbinary(256), ' + @txtpwd + ')'
PRINT @tmpstr
EXEC sp_hexadecimal @SID_varbinary,@SID_string OUT
SET @tmpstr = 'EXEC master..sp_addlogin ''' + @name
+ ''', @pwd, @sid = ' + @SID_string + ', @encryptopt = '
END
ELSE BEGIN
-- Null password
EXEC sp_hexadecimal @SID_varbinary,@SID_string OUT
SET @tmpstr = 'EXEC master..sp_addlogin ''' + @name
+ ''', NULL, @sid = ' + @SID_string + ', @encryptopt = '
END
IF (@xstatus & 2048) = 2048
-- login upgraded from 6.5
SET @tmpstr = @tmpstr + '''skip_encryption_old'''
ELSE
SET @tmpstr = @tmpstr + '''skip_encryption'''
PRINT @tmpstr
END
END
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @xstatus, @binpwd
END
CLOSE login_curs
DEALLOCATE login_curs
RETURN 0

GO
------------------------------------------------------------------------
It also needs sp_hexadecimal:
CREATE PROCEDURE sp_hexadecimal
@binvalue varbinary(256),
@hexvalue varchar(256) OUTPUT
AS
DECLARE @charvalue varchar(256)
DECLARE @i int
DECLARE @length int
DECLARE @hexstring char(16)
SELECT @charvalue = '0x'
SELECT @i = 1
SELECT @length = DATALENGTH (@binvalue)
SELECT @hexstring = '0123456789ABCDEF'
WHILE (@i <= @length)
BEGIN
DECLARE @tempint int
DECLARE @firstint int
DECLARE @secondint int
SELECT @tempint = CONVERT(int, SUBSTRING(@binvalue,@i,1))
SELECT @firstint = FLOOR(@tempint/16)
SELECT @secondint = @tempint - (@firstint*16)
SELECT @charvalue = @charvalue +
SUBSTRING(@hexstring, @firstint+1, 1) +
SUBSTRING(@hexstring, @secondint+1, 1)
SELECT @i = @i + 1
END
SELECT @hexvalue = @charvalue

GO
After restore in new server you have to run the result of:
sp_help_revlogin

Also you can use a SSIS package to move the logins between the instances, depending upon the number of logins that are created on the source instance.

Look at this KBA http://support.microsoft.com/kb/246133 talks about what Luis referred above in addition to using Transfer login task and also http://support.microsoft.com/kb/918992 for your information.