How to write an invitation letter?

How do I write a visa invitation letter to a relative to visit me in Australia?

• I am a student in Australia, I would like mom to come visit me for couple of weeks. She already done all papers and forms overseas and she is asked to have an invitation letter from her son which is me to send her from Australia. Should I need to sign the letter? What I should write? She can sponsor herself as I only have a place where she can come and stay with me. That's all, thanks.

• Answer:

  It's easy. You should address it to the Australian Embassy at your mother's country of residence, and then: To Whom It May Concern, explain the situation (providing your full name, your full address and your status as a student in Australia), finish off by saying that your mum intends to stay from XX to XX (specific dates) and specify where/in which address she'll be staying Leave contact details for yourself such as email and phone number This shouldn't be a problem