What is the meaning of 'Don’t get me started.'
These lines are from sitcom Friends.
Fyi, I put some more lines below.

Alice: (laughs) No. No. No. (Sits down.) Okay, now, see, I wanna name the girl baby Leslie, and Frank wants to name one of the boy babies Frank JR. JR.
Chandler: Wouldn’t that be Frank the III?
Alice: Don’t get me started.

Question

What is the meaning of 'Don’t get me started.'
These lines are  from sitcom Friends.
Fyi, I put some more lines below.

Alice: (laughs) No. No. No. (Sits down.) Okay, now, see, I wanna name the girl baby Leslie, and Frank wants to name one of the boy babies Frank JR. JR. 
Chandler: Wouldn’t that be Frank the III? 
Alice: Don’t get me started.

Answer

Often when one has a large amount of things (mainly negative) to say about a particular topic, this idiom is used.

Example:
Don't get me started on why I can't stand him.

Answer

Aly is right; I'm just going into more detail.  
When someone says, "Don't get me started," it is usually a mock warning.  The expression suggests that they have sooo much to say about a particular subject, you don't really want to listen to all that they have to say about it.