As an educator, I would tell you that all tutorials help learn a new skill! Video tutorials are especially useful and the Sketchup tutorials are no different. In addition to the video tutorials, they offer models to work with "hands on."
Google Sketchup is free. If you are an builder, design houses, or an architect, there is Sketchup Pro for $495.00. If you are not one of those people, then you have no reason to use pro. Its features would be useless to you. Don't think that Sketchup is a program where if you want all the features, you have to buy it. There is nothing like, To use this feature, upgrade! It is free software but if you need more tools to help you build a real house, you would have to upgrade. You can learn more at Sketchup.Google.com
Both the Pro and Standard versions of Google's SketchUp can be used on a Mac. Google provides many resources to help a user learn about SketchUp (See links below) .
There are a number of ways in which one can learn how to program the JavaScript confirm dialog box into their code. One way is by reading the relevant tutorials on the website JavaScript Kit.
HTML is short for HyperText Markup Language, which is a language used to program websites. One can learn how to code in this language by doing online tutorials at websites such as About.
You can learn from books, Internet tutorials. There are lot of tutorials on Internet just type photoshop tutorials in browser. Good starting point are official Adobe video tutorials. See related link.
AutoCAD, Revit, Sketchup, Rhino or 3dMax
First you would need to learn the basics of Photoshop at first it will seem a bit difficult to manipulate but as you use it frequently you will begin to get accustom to the runnings of the program. Click on over to http://psd.tutsplus.com/tutorials/tools-tips/preset-manager-photoshop/ this site provides you with all you need to know about starting and advancing as a pro in Photoshop. Click on Tutorials in the home bar and you are on your way to becoming a Photoshop user or if your still not comfortable with starting off with tutorials you can click on sessions (http://psd.tutsplus.com/sessions/photoshop-tutorials-for-beginners/) and get one on one guide to using the program.
There are many online program tutorials on websites like Youtube. There are also books such as programming for dummies that works well for people with little knowledge trying to program.
You can learn to airbrush and touch up images by using software such as Adobe PhotoShop. This is an excellent program as it has really good tutorials built in and explains things very clearly.
Xubuntu is open source software. There are a number of user forums and free tutorials available online to learn the basics of Xubuntu. The best way to learn is to set up Xubuntu following the installation instructions then search for some tutorials.
Download Visual Basic, Then Go Watch Tutorials on youtube or something, you'll learn over time, at least I did,
search for tutorials on youtube