What it means
始める means to start or begin something. As a main verb, it is used with を to show the activity or thing that someone starts. It also follows the masu-stem of another verb to mean that the action begins. The polite counterpart is 始めます.
Usage note
When 始める follows another verb, use the masu-stem, not the dictionary form. Do not confuse 始める, which usually takes an agent that starts something, with 始まる, which describes something starting by itself.
How to use it
Nounを始めます
来月、父は新しい仕事を始めます。
Next month, my father will start a new job.
Verb (ます-stem)始めます
雨が降り始めます。
It will start raining.
Nounを始める
来月、父は新しい仕事を始める。
Next month, my father will start a new job.
Verb (ます-stem)始める
雨が降り始める。
It will start raining.