Skilled visa (sub-class 189) application (Melbourne)

Hi, are there any expats here whom has applied and now living in Australia with the sub-class Protected content ?

My husband and I are gathering info before we start applying for the visa, can anyone give any tips or things to watch out for? How long did it take to receive the visa?

Also, is it a good idea to use an agent?

Thanks in advance for any advice!

Kelly