angularjs - Few questions regarding Angular directives -

i have few questions regarding angular directives

i'm basing questions based on following block of codes

<ul class='parent'>     <li class='child1'></li>     <li class='child2 active'></li>     <li class='child3'></li> </ul> 

so based on above

• how can create directive based on above (assuming comes angular plugin, , there no angular directive attribute defined within tag)?
• assuming above angular plugin, , don't intend edit plugin, how can use directive see list active?
• how can operations through code above using angular? jquery, can as

for checking child length

$('.parent').children().length 

for iterating through child elements

$.each($('.parent').children(), function(){ console.log(this); }); 

but when tried angular way

angular.element(document.queryselectorall('.parents')).children().length 

somehow part returned me wrong value. guess jquery mindset reason why couldn't value still, read somewhere angular.element object equivalent of jquery $() object, both should able use same functions.

• if want event binding on code above should inside link function correct? if want watch , apply changes code above, should use directive's scope , inside link function right?
• is there easy-to-chew guide on how angular's directives? somehow of read pretty confusing directive guide in angularjs documentation itself.