Home Economics 101

I hope home maintainence 101 is on-topic enough here: I couldn't find a sister community that looked more suitable.

My overall situation: I live with a partner and our baby in an apartment on which we are mortgagers. We've had it for some years. We live in a metropolitan area of Australia.

We need to get some fairly elementary electrical work done and I have no idea how to commission it!I feel like everyone else received a "how to be an adult" book that included this and I just missed out totally. Some of my friends have renovated! More than once!

The work we need done is twofold: we need a powerpoint fixed and we need our bathroom exhaust fan replaced. Just to head off one suggestion at the pass: this is a small building, and does not employ a full time manager or similar, or have a service that organises tradespeople for residents. Under strata title in Australia they maintain the common areas including common walls, we maintain the interior. Also, in Australia licensed electricians have to do electrical work, you can't maintain your own wiring. (And even if it was legal, I'm not competent.)

I can figure out the powerpoint: I go to the phonebook (online), find random electricians in the area and get them to come out. Only one question about that:

(a) is it normal to ask for a couple of quotes on the work, or should I just get whoever agrees to turn up first to do the work? Should I get them to quote, say, an hourly rate on the phone?

Now for the exhaust fan:

(b) do I need to go out and buy a replacement fan myself? I can't imagine that electricians do your shopping for you! But then:

(c) do I get the electrician to come in, tell me what to buy and then have them come back to install it? Or will they turn up and tell me I should have bought it before wasting their time?

(d) do fan units come in a limited range of sizes? I'm not keen on needing to hire a second person to change the hole in the ceiling for us.

(c) is most of the reason I haven't just done it already. I really dislike being in those "you should have known that..." situations.

Edited to add: my difficulty in getting recommendations due to not having a social network in the area comes up in comments. I'm not really looking for input into how to build one though, more in the answers to these questions in the post.

Edited Nov 2010: My final thoughts in comments.