First of all dont be fooled by EVERYONE - make the folders specifically available to the users you want. Make sure that if you are NOT on AD the user has an account with sync'ed passwords on the server and the desktop. Below are instructions for properly setting up the share:
The File and Printer Sharing for Microsoft Networks component allows computers on a network to access resources on other computers using a Microsoft network. This component is installed and enabled by default. It is enabled per connection using TCP/IP and is necessary to share local folders.
The File and Printer Sharing for Microsoft Networks component is the equivalent of the Server service in Windows NT 4.0.
To share folders with other users on your network
1. Open My Documents in Windows Explorer. Click Start, point to All Programs, point to Accessories, and then click Windows Explorer.
2. Click the folder you want to share.
3. Click Share this folder in File and Folder Tasks.
4. In the Properties dialog box select the radio button Share this folder to share the folder with other users on your network.
New Folder Properties dialog box - Sharing tab
5. To change the name of the folder on the network, type a new name for the folder in the Share name text box. This will not change the name of the folder on your computer.
Note The Sharing option is not available for the Documents and Settings, Program Files, and Windows system folders. In addition, you cannot share folders in other users’ profiles.
To set, view, change, or remove file and folder permissions
1. Open Windows Explorer, and then locate the file or folder for which you want to set permissions. To open Windows Explore click Start, point to All Programs, point to Accessories, and then click Windows Explorer.
2. Right-click the file or folder, click Properties, and then click the Security tab
New Folder Properties dialog box - Security tab
3. To set permissions for a group or user that does not appear in the Group or user names box, click Add. Type the name of the group or user you want to set permissions for and then click OK,
Select Users, Computers, or Groups dialog box
4. To change or remove permissions from an existing group or user, click the name of the group or user and do one of the following.
* To allow or deny a permission, in the Permissions for...box, select the Allow or Deny check box.
* To remove the group or user from the Group or user names box, click Remove.
* In Windows XP Professional, the Everyone group no longer includes Anonymous Logon.
* You can set file and folder permissions only on drives formatted to use NTFS.
* To change permissions you must be the owner, or have been granted permission to do so by the owner.
* Groups or users granted Full Control for a folder can delete files and subfolders within that folder regardless of the permissions protecting the files and subfolders.
* If the check boxes under Permissions for user or group are shaded or if the Remove button is unavailable, then the file or folder has inherited permissions from the parent folder.
* When adding a new user or group, by default, this user or group will have Read & Execute, List Folder Contents, and Read permissions.