We used to run a Wedding & Portrait business but gave it up due to family commitments and we were both still in full time employment.
It all started when my wife took some pictures at my cousins wedding but only as a guest. My cousin found them to be better than the 'paid pro' and we gave them a bunch of prints to use how they wanted. (she used film back then).
Someone suggested that she should do it professionally and we considered it and finally took the plunge.
My wife went on a Barratt & Co Wedding Photography course (fairly expensive but very good and taught her as much about running the business as taking the pictures). Soon after that a colleague of my wife asked her to take pictures at her wedding. We agreed and offered our services 'free' as a wedding gift to them.
Using the photos from this we made ourselves a preview album to show customers.
I set up a website and added it too all the wedding listing sites I could find, plus Yell, Tompson etc etc. We paid for a Yellow pages advert (we still get calls, 3 years since stopping!!

)
Gradually we started to get business and at our peak managed 20 weddings in one year, 10 or so portraits and 1 school prom. It was this year that we decided it was too much for us as we had a young daughter and full time jobs.
Wedding Photography is hard hard work!!
A typical wedding:
1) Initial Wedding interviews: 1-2 hours
2) 2nd Meeting to discuss photos, times etc: 1-2 hours
3) Visit venue: 1-2 hours
4) Wedding Day: 4-10 hours depending on package
5) Processing pictures: difficult to say 2-3 days
6) Producing proof album: 2-3 hours
7) Producing proof website: 2-3 hours
8) 3rd Meeting to discuss what pictures they want 1-3 hours
9) Producing final album: 4-5 hours
10) Organising reprints: 1-5 hours
11) Final meeting: 1 hour
Bare in mind this was with normal albums...digi albums maybe quicker!
As you can see this is not easy when you have other commitments as we did.
My advice would be to seriously consider what you are doing. Then, rethink it and if you are still serious then go for it.
Yes it is stressful (though not as stressful as you get told!), it is great fun (on the day), you get an enormous sense of satisfaction when you get thanked by B&G, their family etc etc and you get to see people of perhaps the happiest day of their lives!
Go to a wedding and watch what a 'pro' does and if you get a chance talk to him/her (We had plenty of people chat to us about it all and we were happy to talk). Ask them if you could 'hold their bags' on another wedding to see what they get up to etc. You will probably be surprised how many will be happy to have someone along!
ooh this is a long post...sorry!
**EDIT**
Did it pay our wages? Considering the time spent, possibly not enough to live on. However, Portraits and the Proms that we did, we certainly could have, as the time spent on these was no where near as much as weddings!
**/EDIT**
Good luck.
AB