Hi
Some of the previous advice is the best - trial and error.
When I first converted from Quirk, I spent some free time converting current Quirk jobs to Indesign.
I would export a pdf from QX and place each page pdf into IND on a locked layer, then basically 'trace' over it with indesign elements. Any text can be copied from the pdf and formatted in IND.
This gives you a real project and a goal to reach, sometimes it's best to learn 'on the job', rather than open a blank document and draw a few coloured boxes and say "not much better"
The Adobe site (via the help menu) is a great resource for tips and descriptions of what things do.
Podcasts are also great as they allow you to be shown what is going on. layers tv is great and also the indesigner (a little more advanced, but if you know what can be done then that will only inspire you along the way:
http://www.theindesigner.com/podcasts/podcasts.xml (itunes link)
Don't try to try to use Indesign like you used Quirk, they are worlds apart.
Remember, If you are self-taught, you won't know things that you have not taught yourself yet!
Ask people, including posting on this forum, people are always glad to help, (it makes them feel good)
Good luck using IND