A: Microsoft Lync creates its address book based on information from Active Directory (AD) that’s pulled into its SQL Server database once a minute and then once every 24 hours (by default 1:30 AM). Lync updates the address book based on updated information. Lync clients then download this update at a random interval.

This is why, for a brand new Lync deployment, there might be a delay before clients get the address book.
You can force address book creation by using the following commands:

PS C:\> Get-CsAddressBookConfiguration

Identity : Global
RunTimeOfDay : 1:30 AM
KeepDuration : 30
SynchronizePollingInterval : 00:05:00
MaxDeltaFileSizePercentage : 20
UseNormalizationRules : True
IgnoreGenericRules : False
EnableFileGeneration : True
This first command just shows when the address book update occurs. To force an update to occur, just run this command: Update-CsAddressBook

To check for success, look at the Lync Server event log and four events will be generated:

Event ID 21005 notifies you that the synchronization started, 21010 tells you the synchronization completed, 21056 gives details on the synchronization, and 21004 tells you when the next synchronization will occur.
Examples are shown below:

Log Name: Lync Server
Source: LS Address Book Server
Date: 8/4/2011 1:30:43 PM
Event ID: 21005
Task Category: (1008)
Description:
Synchronization pass started.

Log Name: Lync Server
Source: LS Address Book Server
Date: 8/4/2011 1:30:44 PM
Event ID: 21010
Task Category: (1008)
Description:
Synchronization pass completed successfully

Address Book web service backend data partition = RtcAb1

Log Name: Lync Server
Source: LS Address Book Server
Date: 8/4/2011 1:30:44 PM
Event ID: 21056
Task Category: (1008)
Description:
Synchronization Pass Summary.

Sync pass completed with 13 contacts processed
Number of separate AD partitions: 1
Number of valid contacts: 13
Number of empty contacts: 0
Number of invalid contacts: 0
Number of cached photos deleted: 3
Number of stale OC files deleted: 0
Number of OC full files written: 1 with 13 total contacts
Number of OC delta files written: 56 with a total of 0 new/updated contacts and 0 deleted contacts.
Number of OC bytes written: 41,312 compressed to 29,980 bytes on disk.
Number of stale device files deleted: 0
Number of device full files written: 1 with 28 total contacts
Number of device delta files written: 13 with a total of 0 new/updated contacts and 0 deleted contacts.
Number of device bytes written: 20,720 compressed to 15,309 bytes on disk.

Log Name: Lync Server
Source: LS Address Book Server
Date: 8/4/2011 1:30:44 PM
Event ID: 21004
Task Category: (1008)
Description:
Next synchronization pass will start at:
8/5/2011 1:30:00 AM