Passed the LPI Linux Essentials yesterday.
It is something I have been considerng for a while.
Sunday evening I started to read.
I used the free material from Linupfront.
http://shop-download.linupfront.de/cc/lxes-en-manual-cc.pdf
I have used Unix a lot maybe 10 years ago so much was familiar.
And I passed the test on Wednesday.
Next I'll go for the CompTia Linux+/LPIC-1.
Then I'll have to study more.