Personally, I'm not really off-put by yellowed photos or even slightly blurry ones or whatever - I can see past those imperfections for the subject of the photo, but I like to take good photos just for myself so I can have as accurate of a record as possible.
I imagine I'm not alone on this one. Who doesn't want to capture that perfect moment of a bloom FINALLY opening or that perfect beautiful leaf before the moths and caterpillars get to it? But who really wants to invest in fancy stuff and learn a whole bunch of stuff just to take photos?
I'm all for taking well-lit, beautiful photos, but I'm lazy, don't want to spend a lot of money, and don't want to have a bunch of junk around. So the plan is simple, and there isn't a whole lot to know/understand.
Note: You can always learn more and create a different sort of "studio" and lighting scheme, but this is what I do and it seems to work pretty well most of the time.
Step 1: Lighting
The first thing to know is that most bulbs (the lights, not the plants) you find in the house will cause a photo to be yellow/orange which is really hard to color correct and will take forever to do so and still maintain some integrity for what the plant looked like.
Flashes on cameras will sometimes cause odd lighting if you aren't diffusing the flash or bouncing it off a nearby surface. You can also use gels and filters, but that's tricky stuff. Sunlight is the best kind of light but is difficult to control and isn't always around when you need it.
The only option left for indoor (or controlled) lighting is to use a natural white bulb or a color-corrected bulb which aren't all that expensive, will last a good long time, and are available at big box stores like Home Depot. Use them in bell work lights, which you probably already have if you're a gardener or a DIYer, and you're on your way to a mini photo studio.
Note: I'm glossing over a lot when it comes to photography and light, but this seems to be the most pertinent.