Few useful adb commands :
adb devices – To list android devices
adb logcat – To take dump of the device debug information
adb remount – To remount the device in write mode
adb shell – To access the device shell
adb install – To install the application
adb push – To upload the filesystem to your device
adb pull – To download the filesystem from your device
adb start-server – To start adb server
adb kill-server – To stop adb server