Upload & Sell: Off
Dan if you read "The Right Resolution" as linked Jeff now suggests you print from Lightroom and for images less than 360 ppi upres them to 360 and for images above 360 and less than 720ppi upres them to 720ppi (for epson printers) Let the printer do the work is no longer what he teaches. Though he admits that you really have to pixel peep the see the difference.
I am aware that he changed the specifics of his recommendations after I first saw the material I mentioned. However, my main point about how that material enlightened me about the process and techniques of inkjet printing remains.
The more important thing is that he understands a lot about all of this printing stuff - not that I necessarily agree with everything he or anyone else says today, nor that I will necessarily print exactly as he would. Frankly, there is no single "right" or "correct" way to do these things. Despite the claims of some that their method is the best or only one, a quick look around confirms that there are others using somewhat different approaches, at least as to certain details, that clearly lead to excellent prints.
When he says something about how inkjet printing works, how to prepare prints for printing on inkjet, and about how images are viewed and perceived, his voice is among those that are credible and worth attention.
On the other hand, a lot of what passes for knowledge and which is presented as absolute fact in this and similar forums is more like repetition of nostrums (often misinterpreted), speculation, out-dated, and wholly ungrounded in actual printing.
For the record, I now sometimes do upres in software rather than letting the printer do all of the interpolation, but this is a selective choice based on the print I am working on at the time. I would never worry about taking steps to increase resolution beyond 300, though I still allow resolution to float higher in very small prints, where I do allow the printer to do the interpolation.
(I still haven't, despite trying and despite the recommendations of some well-known photographers I know - switched to LR for printing or for file management or for basic post-processing work. It's a weakness! I still like my photoshop workflow. I'm strange that way! ;-)