Q: How I use iMessage between my devices?

You can only iMessage other Apple devices.

iMessage must be turned on in settings.

iPhones can sign in with their cell numbers, but iPads or iPods must use email to sign in to iMessage.

The people you are trying to contact must also have iMessage turned on and signed in with email or cell phone number.

About Messages

http://support.apple.com/kb/HT3529

Activating FaceTime and iMessage

http://support.apple.com/kb/TS4268

Trouble-shooting iMessage

http://support.apple.com/kb/ts2755

.....to message wifi devices, they must have wifi connection to get the messages.

Using FaceTime http://support.apple.com/kb/ht4319

Troubleshooting FaceTime http://support.apple.com/kb/TS3367

The Complete Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting

http://tinyurl.com/a7odey8

Troubleshooting FaceTime and iMessage activation

http://support.apple.com/kb/TS4268

iOS: FaceTime is 'Unable to verify email because it is in use'

http://support.apple.com/kb/TS3510

Using FaceTime and iMessage behind a firewall

http://support.apple.com/kb/HT4245

iOS: About Messages

http://support.apple.com/kb/HT3529

Set up iMessage

http://www.apple.com/ca/ios/messages/

iOS and OS X: Link your phone number and Apple ID for use with FaceTime and iMessage

http://support.apple.com/kb/HT5538

How to Set Up & Use iMessage on iPhone, iPad, & iPod touch with iOS

http://osxdaily.com/2011/10/18/set-up-imessage-on-iphone-ipad-ipod-touch-with-io s-5/

Set Up Alert Sounds

http://www.quepublishing.com/articles/article.aspx?p=1873027&seqNum=3

Extra FaceTime IDs

http://tinyurl.com/k683gr4

Troubleshooting Messages

http://support.apple.com/kb/TS2755

Troubleshooting iMessage Issues: Some Useful Tips You Should Try

http://www.igeeksblog.com/troubleshooting-imessage-issues/

Setting Up Multiple iOS Devices for iMessage and Facetime

http://macmost.com/setting-up-multiple-ios-devices-for-messages-and-facetime.htm l

FaceTime and iMessage not accepting Apple ID password

http://www.ilounge.com/index.php/articles/comments/facetime-and-imessage-not-acc epting-apple-id-password/

Fix Can’t Sign Into FaceTime or iMessage iOS 7

http://ipadtutr.com/fix-login-facetime-imessage-ios-7/

FaceTime, Game Center, Messages: Troubleshooting sign in issues

http://support.apple.com/kb/TS3970

Unable to use FaceTime and iMessage with my apple ID

https://discussions.apple.com/thread/4649373?tstart=90

How to Block Someone on FaceTime

http://www.ehow.com/how_10033185_block-someone-facetime.html

My Facetime Doesn't Ring

https://discussions.apple.com/message/19087457#19087457

How to watch FaceTime calls on the big screen with Apple TV

http://www.imore.com/daily-tip-ios-5-airplay-mirroring-facetime

Send an iMessage as a Text Message Instead with a Quick Tap & Hold

http://osxdaily.com/2012/11/18/send-imessage-as-text-message/

To send messages to non-Apple devices, check out the TextFree app https://itunes.apple.com/us/app/text-free-textfree-sms-real/id399355755?mt=8

How to Send SMS from iPad

http://www.iskysoft.com/apple-ipad/send-sms-from-ipad.html

How to Receive SMS Messages on an iPad

http://yourbusiness.azcentral.com/receive-sms-messages-ipad-16776.html

Apps for Texting http://appadvice.com/appguides/show/apps-for-texting

You can check the status of the FaceTime/iMessage servers at this link.

http://www.apple.com/support/systemstatus/

 Cheers, Tom