Liferay Learning resources

Various resources which a person can use to learn Liferay

The best option is to go through the official documentation its available in multiple formats. Official documentation is a comprehensive resource for developers.
web / online - https://www.liferay.com/documentation/liferay-portal/6.2/user-guide
                      https://www.liferay.com/documentation/liferay-portal/6.2/development

print - http://www.lulu.com/shop/rich-sezov/using-liferay-portal-61/paperback/product-21014853.html

downloadable pdf  - new version pdf will be released soon

Liferay also offers trainings in different modules, person can enroll for these trainings as per their requirements.
I would recommend undergoing  Mastering Liferay fundamentals before taking on developing for Liferay platform course

https://www.liferay.com/services/training

There are many videos available on youtube, search with keyword + liferay
Video of Liferay web events along with slides are available at - https://www.liferay.com/events/web-events

If you are stuck with any issue or need expert help , community resources like wiki, blog forum are best place to seek pointers - https://www.liferay.com/community/welcome/dashboard

Books from independent authors are also available in print and ebook format.

Also join various active Liferay user group where people meet regularly and share their knowledge.

Liferay CE vs EE

It has always been a big question which edition of Liferay should someone use and what are the difference between the various edition.

Liferay offers Liferay portal in two edition the first one is the community version  popularly called as CE and the other as enterprise edition or EE

In my personal opinion CE should be used in project which are not mission critical and have a limited scope.
Enterprise edition comes with a gamete of functionality and is much robust than CE
The enterprise edition comes with Liferay's product support which is offered through the enterprise subscription.

https://www.liferay.com/products/liferay-portal/ee/overview

Check the comparison Tab

FAQ

Q: Is it possible to move my existing solution from Liferay CE to EE
A: Yes, its possible to move from CE to EE however the custom components and other custom functionality need to be rebuild / recompiled using the EE sdk.

Q: Is it possible to develop a new project on CE and then move to EE
A: It is almost like moving from CE to EE and its not a good approach as migration effort is required alongwith manual effort of rebuilding the apps / custom functionality with EE sdk.
EE edition and Liferay developer studio for EE (LDS ) is available to free 30 day trial.

Q:What kind of support Liferay offers
A: https://www.liferay.com/products/liferay-portal/ee/service-levels