I highly recommend getting or at least reading through Katrin Eismann's books on photo retouching if you are serious about doing retouching. One of the best resources for techniques you'll find. Not always beginner stuff, but easy enough to follow after you've gone through it a couple times.
For printing, ronmatt is right, there aren't such things as RGB printing presses per se... but there are times when you would want to leave your files in RGB. Unless you're doing logo work or something similar, work with photos in RGB and then save a copy in CMYK to go to the press. The editing environment is better in RGB and you will have access to more tools as well as a larger color gamut. Working in L*a*b is okay too, if you know how.
Now, if you're planning on printing off a desktop printer like say, and inkjet (especially inkjets)
do not convert to CMYK, always work and stay in RGB. Desktop printers assume that you are working with RGB files and if you send them CMYK, they will convert them as if they were RGB and the colors will look like they are made of mud. Just stay in RGB.
ronmatt said:
One very important piece if advise though would be, if your going to be making color adjustments, make sure your monitor is calibrated properly
This is one of the most important things you can do. If you are planning on doing a lot of work where color accuracy is important, then you should consider purchasing a hardware color calibration setup. At the very least, you should run through Colorsync or Adobe Gamma to generate a calibrated profile for your monitor. This is more important with CRT, which have more accurate color but can shift more. While LCD can shift color, there isn't as much that you can do with it... and Adobe Gamma wasn't really designed to work with LCDs so the more you shift away from it's default the less luminosity you will have. It's a little tricky to do LCD with visual calibration like Adobe Gamma also due to their inherent visual color shift, even on new LCDs.
ronmatt said:
I'd recommend 'not' using any color profiles. or ICC tags.
This is just plain wrong. Unless you are specifically told not to work with color profiles by a printer (usually because they haven't updated their equipment in the last 20 years) then you should always work with a color profile. That color profile should be a standard color profile too (do
not use your monitor color profile). Use something like sRGB or AdobeRGB1998. Working with a color profile is what allows all that careful calibration to continue on to the out put device. That profile is what tells the hardware what colors are supposed to look like. Without that, there's hardly any point in calibrating or adjusting because you're just relying on luck at that point. Any modern print service bureau should be dealing with color profiles, and honestly, if they aren't... find a new one. For home printing, it's slightly less important since your desktop printer is directly hooked to your computer, but it's still helpful. And should you ever want to take the file somewhere else, you won't have to worry about correcting the color again (hopefully).
ronmatt said:
As to unsharp masking, if you change the size and or resolution, it's best to use 'some' throughout the process.
Photoshop automatically does a special unsharp mask every time you scale an image. So whenever you change the size it's automatically applying it to attempt to preserve the per pixel contrast. If the image needed sharpening of highlights before, then it will after a resize too. If it was okay before, then it will still be okay most likely. (Although, most images can use a little sharpening of some kind or another). Changing resolution has no effect on what the pixels look like. Resolution is purely a print conversion tool. You can have a 72dpi image and convert it to a 1200dpi image... and not one pixel will change. When you check "resample" you are actually scaling the image to fit with a resolution choice.... that is scaling... not changing resolution. Understanding resolution is a tough one for beginners and seasoned graphic artists alike. Sooner or later it will throw you for a loop... especially when dealing with multiple output devices.
