If you really want to be successful at brewing, you need to learn and understand the entire process. I'd say buy a beginners book and run through it. I started with
The complete joy of home brewing. It was an awesome book and it had tons of useful info. The instructions are just a guideline really.
Having a wort chiller is doing it right
so you have that, but here are some more suggestions.
Get a hydrometer and testing cylinder.
Use gallon jugs of purified water from the store. This way you don't have to mess with water quality. Also it adds consistency to the process.
Make sure your fermentation temps are within range for the yeast and are consistent.
Do a secondary fermentation, but don't rack to it until primary final gravity hasnt changed for 2-3 days. This is the only way to know primary is finished. The instructions just give a rough estimate hence why the hydrometer is so important. If you do a full secondary and still have haze, use some super kleer in the secondary. Do it without your first time though.
If you cant get bottle carbing down, go to kegging. Makes everything go super smooth, just requires some investment. Chances are though, if you're putting in the right amount of priming sugar and you get bottle bombs, your fermentation wasn't complete. If your beer isn't carbed yet let it sit and remember you gotta keep the bottles at room temp. If you bottle then refrigerate the yeast will go dormant and you'll get flat beer.
Buy brewing software like Beersmith. It gives a lot of insight into ingredients and how they affect your brew. It is also an awesome way to track the progress of your recipes and revisions you make each time you brew them.
There are a lot of people the just do 1-3 gallon batches. This way they can brew often and not have way too much beer to drink. This would be the fastest way to gain experience
If you know someone more experienced with brewing ask them if you could hang out on their brew day and take notes on things he does that you dont.
Anyone can pitch yeast and make beer. To make Great beer you need to take the time to learn the process, keep consistency in your batches, and most of all brew as much as you can.