Then I've read somewhere on a forum (where I can't remember) that (I don't know if its true/correctly reported) when Jeff Schewe has to enlarge a photo does not mind to the resolution because the printer's software will in any case do it (360ppi in this case because I own an Epson). Is this correct?
Ya know, "somewhere on a forum" is kinda a statement that is pure "folly". Exactly WHERE did you read this and EXACTLY what was I supposed to have said and exactly WHEN was this supposed to have happened?
Seriously, if you don't know the answer to above, you would be a fool to presume to know WHAT the FRACK I was talking about...
This is typical of accumulated knowledge in the internet age...the more you spend time on line, the less you actually know.
First off, do you know how to output sharpening? If you do, continue to #2, if not, return to go and start over...
#2, If you: A) know what capture sharpening is and know how to deploy it, continue to #3, if not, return to one and continue the endless loop until you realize you don't know nothing and need to start over...
#3, if you know what you are doing, you're outputting from Lightroom 2.5 and using the built in output sharpening of Lightroom. If you are using Lightroom 2.5 and are NOT using it for output sharpening, return to #1...
If you understand what the effective resolution of today's output devices are and know when and where to upsample, then let's talk...if not, return to #1 and start all over again...
There are indeed "accurate" and "correct" answers to the questions you ask, but it's not at all clear you would understand the answer...
Sorry to be, uh, "pointed" in my answers to your questions, but when you use my name in a manner not at all accurate to what I have and have not said, ya kinda gotta expect some blowback...