You're where I was about 3 months ago. Don't give up--you're well on your way to understanding how to make 95% of your beer (the water)taste better.
Here's what I'd suggest:
For those who want to delve into it more, there are numerous forums (i.e., AHA) and articles online (John Palmer's "How to Brew" and deLange's Alkalinity articles are superb). It is a lot of chemistry and it does take a while to get the concepts, particularly when they're buried in a bunch of equations (I like that JP proves his recommendations, but it does make my eyes glass over). Greg Noonan's book (New Brewing Lager Beer, Brewers Publications, 1996) has 40 pages on water treatment alone.
Figure out your water profile for where you live.
Figure out what water profile you need for the style of beer you're brewing. I used BeerSmith.
Get an inline activated charcoal water filter (the RV filters are about 20-25 bucks at Walmart in the car section)and hook that up to your hose--keep the flow rate low. Get a small plastic hose shut-off valve attachment at HD for a buck-fifty so you can control it better than the spigot by the house.
Get some water cooler jugs (empty ones are about 7 bucks at Walmart and they come with caps). The water supply places like Culligan can do the same. RO water is just 30 cents a gallon at Publix. The amount of distilled or RO water versus local water varies by water profile required by the recipe. Adjust accordingly.
Buy your brew salt additions. Yes, get them all—the 5 major ones are chalk, gypsum, calcium chloride, baking soda, and Epson Salt. The last two you might be able to find at the store, but the first three, and any others, you'll need to go to your LHBS or online. They're not expensive, at all—usually less than 4 bucks for 4 ounces.
Buy a scale to measure very minute amounts of salts—usually less than 20 bucks online.
These are good brewing water chemistry websites to check out if you want to do the calculations and you don't have BeerSmith.http://braukaiser.com/documents/Kaiser_