Things for consideration before choosing Google Apps:-
1. Regulatory issues - If you work in heavily regulated industry, such as finance, you might need to monitor each emails being sent and received by your staff. Currently Google apps do not provide such features.
2. Privacy - Google stores all documents, contacts and other application data automatically. Your information will be kept on Google servers with no guarantee it will be deleted. Storing and using Google Apps online opens up numerous privacy issues with little real comforting assurances.
3. Limitation of users - When using Google Apps free version, you only limited to create up to 10 users. You might need to pay $50 per year for each additional user.
4. Limitation of emails - When using Google Apps free version, you only can send up to 500 emails per day. Each account will be allocated 7.6GB storage and there is additional fee for more.
5. No email aliases - Gmail does not offer traditional email aliases, such as auto forwarding all emails (To, CC, BCC) to a list of other mailboxes. Hence, it might be difficult if you have email aliases which working previously.
6. Additional user and technical support will cost you $50 per user per year. You will get a phone number you can call in the unlikely event such as your account data is hacked or corrupted.
7. For Google Apps free edition, you are offered a support forum and FAQ setup, which is to say you are on your own to figure out most problems.
Shall you would like to proceed to point your domain to Google Apps, kindly you may refer the guidelines below:-
Guidelines to setup Google Apps for your domain