I am not interested in making picture frames at this time, but started thinking how to make one. Suddenly realized my first priority would be making the corners perfect; I would not be pleased with corner gaps. Once I got that down pat, I'd get me a batch of about foot long sample pieces, then start seeing what I could do with various router bits. I'd start with what I had, look those over, then buy individual bits you think would work.
As far as staining, now I use acrylic latex for any staining I do. Take a spoonful or two of various colors, thin with water, try on sample pieces, then thin more, or start another batch thinned less. You can make all sorts of custom colors, but if you want to create the same color again later, it would pay to make detailed notes of every batch you make, even if you toss it, so you can easily duplicate colors later. You can also use this as fabric paint, works as well, or better, then store bought, and is lots less expensive. Cost less than wood stain also. There are other things you can use to stain with also, tea, coffee, tobacco juice, nut shells, tree leaves, and all sorts of things more. Can give some lovely results, but I didn't care for the length of time some of it took - tea dried very rapidly, coffee took several days to dry, walnut and hickory nut husks had to soak beforehand, and so on. Very inexpensive tho.