Hello Cathy - congrats to your sis!
I got married last year, but did it overseas in Orlando. It depends what you're sister wants really as it's the brides day.
You can get good books that takes you through very step, from picking the dress, planning reception, guests lists, stationary, how to plan seating arrangements, flowers, themes for wedding, legal issues on ceremonies, wedding presents,how to deal with difficult relatives, cakes, favors, photography and even honeymoon. I'm from the UK, so you'll have to go to your local store and ask reception.
If she's planning to get married overseas (as most people are nowadays), I planned everything through Virgin Atlantic - they have a very good wedding dept, that is very proactive on the brides behalf. Other travel companies have the same thing, it depends on what the brides wants and the packages they offer.
You could look at this UK web site, it's got very feature covered - http://www.confetti.co.uk/
As a final option for ideas, pick up some wedding magazines, they have lots of ideas and even count down list of what you/sis should be doing until the final day.
I hope that helps!!