So I will try to use one catalogue, makes sense to me.
now should I import everything in one step, go on holyday for a week while it is rendering previews and then try to organize it or should I import chunk after chunk?
Holiday time is always good,
I look at having digital images as two different things: a data storage system and a workable photo working system. As a data storage system, I want my files stored where I have some hope of locating a specific file. I store all my image files in a date oriented folder structure:
20050311 dog show shoot
20050311 Alicia portrait shoot
20050320 View over harbor
I put them there using windows explorer (mac finder), independent of lightroom. I set up backup mechanisms against this basic orignal file work area outside of lightroom. Then I import them into lightroom. When I first brought in 2005, I found the easiest way was to copy a single photo directly under 2005, click import in lightroom and import using choose files and went to that folder and chose that file. Then I clicked on the folder and asked lightroom to synchronize. Had a cup of coffee or two. Came back and confirmed that I wanted all thousands imported. Went out and mowed the lawn. Came back and everything was in the catalog, nicely arranged into my folder structure, ready for me to build collections, put in keywords, etc.
Once working with them in Lightroom, I found I needed to export jpg for uploading. I exported them to a new folder called upload under photos, so now my backup archive includes those as well. I should probably delete them after I'm done uploading, but then I'd not remember what I'd uploaded (or where, sub folders under upload). Collections to the rescue. I make a collection, say "Best picks from view over harbor", I export that to what amounts to temporary folder and then upload from there. I've got a record of my upload in the collection, but I don't really need the uploaded files -- well, maybe not. Might be situations where I would want to keep copies o those jpgs.
Same kind of thing with prints, though here I'm much more likely to want to keep a copy of the file I made the print from.