Sanding off the old finish is NOT a good idea. First, the veneer is likely to be VERY thin and it is very easy to sand through. Second, sanding does not do a very good job of preparing the surface for new stain. Trying to "stain" wood without removing the original finish (a process really called "toning") is challenging, best requiring spray technology, and significant experience in using it.
The better way of removing old finish is with chemical stripper. The most effective strippers include methylene choride. It is noxious and should be used only with excellent ventilation, and with gloves, aprons and eye protection. I wouldn't recomment this if you aren't naturally pretty neat, since if you slop it around you could damage drivers, etc. This is also a product where READING all the directions is a very good idea.
With all the old finish removed, and the surface rinsed as directed. You can choose a stain. The names mean nothing, look at the color on a sample of similar wood. I'd avoid Minwax, in favor of brands like Old Masters, General Finishes. Oak takes stain well, you do not need "pre-stain conditioner". Do not chose stain mixed with finish such as PolyShades--these can end up looking like streaky messes. Choose standard oil based stains--waterbased stains are tricky to use--ease of clean up is not worth it.
For a top coat over the stain, I would use a wipe on varnish. Although I'm not fond of their marketing, your easiest choice is likely to be Formby's Tung Oil Finish. I'd choose the satin over the gloss. This product has essentially nothing to do with Tung Oil--it's just an alkyd varnish, based mostly around soya oil, which is relatively light colored and which doesn't turn as yellow over time as some other varnishes, such as those labeled as polyurethane. I'd wipe on about 4 or 5 coats using a lintless shop towel (like the blue ones y ou find in paint departments). Apply the wipeon very thinnly, following the image you see when a bus boy wipes off a restaurant table. You can apply several coats (up to three) in a day, applying the next after the previous coat has is dry to a gentle touch. After three coats, let it dry over night, then lightly sand the surface using a sanding block and 320 or 400 grit sandpaper.