Those of us who are old enough will remember a time when you paid for a software package and it came in a box containing a handful of floppy disks and a user manual. Not some web-link to a bunch of HTML pages, but an actual book, made from real paper that had previously been the home of a Norwegian Blue.
Those days are long gone. There was a tendency for people not to read them (hence the RTFM phrase which preceded JFGI) and it obviously saved the publishers money if they didn't print them. It also made the package a lot lighter. So the book gradually migrated to a PDF on the installation CD-ROM. But if you wanted the documentation to actually match the product, then you couldn't finalize the manual until after you finish coding and adding a delay there impacts your release date. So the PDF got reduced to a 'readme.txt' which pointed you to a web-site. Some software houses provide a decent set of documentation, often available for free download. Others have a forum for asking questions which may or may not get answered one day.
So, without a manual, we just jump in, hammer away at the keyboard and mouse until it breaks and then Google for a way to fix it. Sometimes it helps to take a step back.
I've spent a few days reviewing Packt Publishing's SQL Developer book, courtesy of the publishers. This book very much fits in the mould of the manuals that used to come with software. While it is not an Oracle Press book, it is by Sue Harper who is in charge of the product at Oracle, so it feels like the 'official line'. I remember attending a workshop she gave several years ago when she was spruiking ADF and J2EE to Forms Developers.
Overall the book would be excellent for an individual or team new to SQL Developer, especially those moving from good old SQL*Plus. The bit on the PL/SQL debugger would be especially useful to developers. [New year's resolution - DBMS_OUTPUT is not the only way to debug.] It struck me that there's room for more information on migrating scripts from SQL*Plus to SQL Developer, but maybe there's a blog post or two in that. If you are moving from TOAD or similar, then you may not get out as much from it, but it will lower the frustration levels in locating comparable functions.
I've been using the tool since it came out in beta as Raptor (and still prefer that name).I still got a few nuggets out and its pushing me to do more with customised reports and other simple extensions (ie those that don't involve Java). There's not as much in it for the experienced user, but maybe get your boss to buy a copy for the team and pass it around. At the least, when you employ the next newbie, they can read that and not interrupt you to ask how to generate a table script !
I agree with Lewis's review that the omission of details on the Unit Testing component is unfortunate. I also skipped the Data Modelling chapter as, at $3000 for an individual license, it is not something I expect to come across any time soon.
You can read a sample chapter here. It will give you a feel for the writing, but it is too limited to be of help to a total newbie and will not tell anyone experienced anything new, so it isn't the best taster. It does include a precis paragraph on each chapter though, which is worth reading through.