I suppose some discussion of various brands of ingredients is in order.
Flour: That’s sort of a well, it depends sort of deal. For bread I don’t use anything but King Arthur flour. Higher protein than most. Totally consistent. I can’t address keeping characteristics since I go through it so fast. I haven’t found anything superior or even equal to the King Arthur. Good web site: http://www.kingarthurflour.com/. The local grocery stores carry the all-purpose, bread, and wheat flours. They don’t stock the rye and high gluten varieties, but those can be ordered from the web site and the shipping is only mildly prohibitive.
Here’s the “it depends” side of things: King Arthur is absolutely terrible for pie crusts, biscuits, and cakes. For anything Southern like biscuits, pies, etc., you want a Southern flour like White Lily or Martha White. Southern flour is made from different wheat and is much lower in protein. Southern flour makes lousy bread but great pie crusts and biscuits. If your grocery store doesn’t carry Southern flour, order it off the net. Yankee flour cannot make a decent biscuit. Southern flour doesn’t make good bread. All regional chauvinism aside, them’s the facts, ma’am.
Cookies and such I generally use King Arthur all-purpose and haven’t had any problems.
For oddball stuff like rye berries and such, I use http://www.barryfarm.com/ website. They have all kinds of things for the serious baker.
The one bread that I can think of that you might not want to build with King Arthur would be a real French baguette, then you need to use French flour. A different protein and ash and chemical content in the French flour makes a bit of a difference in the bread. French bread, indeed. What we call French bread is pretty recent, like WWI vintage. It actually came from Austria, and some of the old French still call it Vienna Bread. I have seen people get close by blending ap flour and bread flour. This may get you close to the correct protein level, but it won’t get the exact flavor provided by the different ash and chemical content. The King Arthur website lists a French-Style flour. I haven’t tried it so I can’t vouch for it, but they are usually pretty reliable.
For cakes, use cake flour. I don’t do cakes so I can’t really pontificate about the qualities of the cake flours. My daughter is the cake expert, not I.
Sugar: Around here Dixie Crystals is what we use. I suppose that it is pretty well available in most parts of the country.
Butter: The Land O’ Lakes is the normal butter of choice. Consistently good. We can also get a European butter, Plugra. Very good stuff, but a word of caution. Plugra contains more butterfat and less water than American butter, so it is not a 1 to 1 substitution in baking. You will have to adjust the recipe for about 2% difference. 2% doesn’t sound like a lot, and for small batches, it isn’t. But if you are making a large batch be aware of the difference. Of course, if you can get the real country butter do so. I remember that stuff from when I was younger. Marvelous rich taste. Actually, I would recommend the Plugra or country butter be reserved for table use and stick to Land O’ Lakes for baking, since consistency is necessary in baking.
Water: Water is going to make a huge difference in your baking. If your tap water is ok you still want to let it sit overnight before using it in baking so that the chlorine can dissipate. Chlorine makes yeast die. Not good. A good filter like the Brita or Pûr is beneficial. If your water is just no good then get some good quality bottled water for baking. Make a big difference, it does. Another plus of letting water sit awhile is that you generally want the water room temperature, not tap temperature. For a really good discussion of temperature in baking see Jeffrey Hamelman’s book Bread.
Salt: I use kosher salt exclusively for baking. There is a catch to this. You cannot assume that a teaspoon of table salt and a teaspoon of kosher salt is the same. It is not. Kosher salt is a much courser grind. What you want to do is weight, not volume. 10 grams of table salt and 10 grams of kosher salt are equal in salinity, but the 10 grams of course kosher salt is going to occupy a larger volume than the 10 grams of table salt. I do not use sea salt for baking since I cannot be guaranteed that each batch is chemically the same. Sea salt is good for general cooking where you adjust by taste.
Spices: In general I use McCormick, they are consistent and readily available where we live. Your mileage may vary where you live.
Yeast: I use the Fleischman’s Active Dry yeast in the packets. I have had no problem with this stuff. I do proof the yeast in some warm water with a pinch of sugar, even though this is technically not necessary. I really like for my yeast to be alive and awake before I add it to the mix. Don’t use the Rapid Rise, the idea there is that it will eliminate the first rise. The multiple rises enhance the flavor of the bread. Why would you want to eliminate a flavor enhancing step?
Bread machines: I don’t like them and don’t use them. I want more control and direct involvement with my bread. There are many people who do use them and get semi-decent results. Use your own judgment.
Mixer: Kitchenaid. The dough hook does a very decent job and I no longer have the hand strength to do prolonged kneading. I haven’t seen any other mixer that compares. If you can afford it, get the larger lift bowl type, but the hinge top will do the job just fine.
The first and last rule of baking is: Use the best quality ingredients you can get. If any of your ingredients are out of date or stale, toss and replace. Why go to the time and labor or making something with inferior ingredients?