when new dabase created how can I gave the access permission to all users in server?

First of all I would not blindly give all the users permissions in one go without reviewing it. It could lead to a very bad situation. So for the sake of less work and simplicity but with a better approach could be to have a batch printed which would be run after reviewing thoroughly. Following is a snippet which would add all SQL Logins which are not disabled to db_datareader database role. (CURSOR used intentionally, so modification could be easy)

 DECLARE @SQLLoginName sysname

 DECLARE ServerPrincipals CURSOR FOR
 SELECT [name] 
 FROM sys.server_principals
 WHERE [type] = 'S'
 AND [is_disabled] = 0

 OPEN ServerPrincipals

 FETCH NEXT FROM ServerPrincipals INTO @SQLLoginName

 WHILE @@FETCH_STATUS = 0
 BEGIN
 PRINT 'CREATE USER ['+ @SQLLoginName + '] FOR LOGIN ['+ @SQLLoginName + ']
 GO'
 PRINT 'EXEC sp_addrolemember ''db_datareader '', '''+ @SQLLoginName +'''
 GO'
 FETCH NEXT FROM ServerPrincipals INTO @SQLLoginName
 END

 CLOSE ServerPrincipals
 DEALLOCATE ServerPrincipals

For simplicity have all of your users put into an active directory security group then add that group to your server logins and then add that login as a database user with the permission you need it to have

If you are worried about fixing orphan users after a restore of the database run the following query to fix them.

-- This will report the orphan users.
sp_change_users_login  @Action =  'action' 

-- This will fix the orphan users. e.g This mapps the user "MyUser" to the login "MyUser".
EXEC sp_change_users_login @Action = 'Update_One', @UserName = 'MyUser', @LoginName = 'MyUser'

-- Execute the following query in "Result to text mode" (ctrl+ T) to genrate script for fixing the orphan users. copy the results and run in new window.
SET NOCOUNT ON
USE MyDB
GO

select 'EXEC sp_change_users_login @Action = ''Update_One'', @UserName = '''+name+''', @LoginName = '''+Name+''''+CHAR(10)+'GO'
from sysusers
where issqluser = 1 
and   (sid is not null and sid <> 0x0)
and   (len(sid) <= 16)
and   suser_sname(sid) is null
order by name

If you want to have this setting applied for all databases which are still to be created on a server, you could try making the changes in the model database first, and then create the databases.

The model database is a template for the creation of new SQL Server databases. For more information about what can (and cannot) be done here, see: http://msdn.microsoft.com/en-us/library/ms186388.aspx