windows 2003 server [beginner]

hi,
I am beginner in the field of Networking, I am trying to convert my
organization setup from Workgroup to Domain. For this i have done the
followings,

1) Installed Windows 2003 server on a machine
2) Installed AD (create domain www.abc.com)
3) Create OU (for each dept like I.T, HR etc)
4) Create two groups (Admin and Staff)
5) Add users in OU and relate them to a group. (users are alo member
of "Users")
*Note every thing is going with default settings.
6) Start adding user PCs on domain (users have Windows XP installed)

Here i am facing some problems,

1) Users previously sharing there printer are not unable to share it
now.
2) Some users are facing problem to write data on there local drives.

Would you please suggest me what to do ?

Waitng....

.