How to send a sensor reading through arduino-xbee api

I am trying to send a ultrasonic sensor reading and/or a temperature reading, taken from sensors connected to an arduino with an xbee s2 in api mode.

The readings will be 3digit maximum, (0-300). Can you show to me how i can convert these readings to bytes and how to read them afterwards?

Also, i can send ascii, is it easier to send it like that? (and how i will syntax it, i can send Serial.print('D') but how can i send an integer for example?)