I really never use shellac, so I may not be the best resource on that. I also don't think I would ever use solely wax, though some people do that. I like my woods to look natural and typically don't want a high gloss. I find myself using Danish Oil or Arm R Seal. Danish Oil is an "in the wood" finish. You let it soak and remove the excess from the surface. Arm R Seal does have some polyurethane in it so can build coats on the surface. I don't work with pine but most finishes will add at least a slight amber hue. For a bedside table I'd want some protection so would think Arm R Seal could work well for you. This book is great .
The advice I will give will reproduce (some of) the steps I performed to make my guitar. I put aniline dye on ash.
Get a piece of alder similar to the one you're using for your guitar. Practice spraying dye on. Make sure you do both the face grain and end grain, and are happy with the results. Look at it while wet for the best idea of post-finishing look.
Alder is known to have blotchy tendencies when adding dye. If you spray on very light coats of dye, the problem is mitigated. Some recommend a light wash coat to prevent blotchiness, but this will limit the depth of color you can apply, and if your wash coat is uneven, your color will be uneven. So I prefer not to use a wash coat. You can always experiment with both techniques and find out what works for you.
> I'm not hoping for perfection but I would like it to look decent (better than it does).
I know what I proposed above is a good bit of work. Trust me when I say it's worth it. You will have this guitar for the rest of your life. You want it to look good and be proud of your work. Now go forth and make an awesome guitar ;)
If you want more information on finishing, a good source is Understanding Wood Finishing.
A few things:
In any case, mineral oil is not a real wood finish as it does nothing to protect the wood and eventually evaporates. You evidently don't know much about wood finishing, here's a good book on the subject to get you started.
This one is worth buying and having as a reference on the shelf.
Non-drying oils aren't common wood finishes. By far the most common oils used as wood finishes are linseed and tung oil which are both drying oils. Read this article by Bob Flexner regarding wood finishes and food safety. I highly recommend this book by the same author regarding wood finishes in general.
Here's what I learned the hard way: advice on the internet and blogs is shitty. Read a book and you'll actually learn something.