There's no shortage of online links to follow. You should also find a fitter that will take the time to explain why the combination picked for you is your best. That's what their responsibility is. Iron and wedges are generally selected to get about 10 yards of distance between clubs based on their loft. While some vendors may have a loft of fewer degrees lower so their 6 iron will go further than another 6 iron, distance is only one factor, You need to control the distance after landing to be a scratch golfer. Mid to high handicappers get the most benefit from getting fit. Getting to scratch will take both getting fit and a swing coach if you are more than single digit today. The order in which you do makes a difference. If you need some swing changes, you'll want to start that before/while getting fit so you don't get fit to a bad swing. Good luck.

Hi Jillian,
I am by no means an expert or scratch golfer but I personally feel that getting custom fitted is important. A couple of years ago when I just started golfing I used some standard length and lie clubs. I decided to buy a set and get properly fitted for the clubs. I am much more of a consistent golfer now. Undoubtedly, a lot of that comes from analyzing my swing and spending time at the range but if nothing else, knowing I have the proper equipment is a huge confidence boost. I did a quick google search for you and found a couple of links that I think help explain lie and loft.

noswetgolf.com/LoftAndLie.aspx
www.golfbidder.co.uk/.../golf-club-loft-and-lie-buyers-guide.html

If you want to be a scratch golfer. Practice, continued learning and or lessons and most importantly...get fit. Getting fit will aid you with your game. The clubs will be made for your game/tendencies.

I would definitely find a PGA fitter and get the correct shafts and lies for your swing. I would not go to a big box store for this except as a last resort. A PGA fitter usually with charge a small fee for their time regardless if you order clubs through him or not. You can check to see when vendors are going to have a demo day in your area. The only thing with this is that you will be one of many people trying the vendors different clubs and shafts. The vendor is trying to serve as many people as he can in a short amount of time. Another way is to make an appointment with your local golf clubs public and private who may have a PGA professional who can fit you. I would also ask if the fitter uses some kind of doplar radar machine such as Trackman or FlightScope to gather data to find the best combination of club/shaft and lie for you. The big box store will have some kind of simulator but I have found they do not have a lot of shafts that are available that may help you be a better golfer that a certified professional fitter would have regardless of the manufacture that you choose.