Quick Reference guide of dot operators:

.length
// counts the number of items in an array

.nodeName
// reference the name of the node, i.e. p for p tag, etc.

.parentNode
// references the parent on an element node

.childNodes
// references the elements of children. i.e. the parent can be a <ul> tag and the children would be the <li> tags. You reference them as you arrays, .childNodes[0] onwards.

.firstChild
// as above, but just gets the 1st child... same as .childNodes[0]

.lastChild
// as above, but gets the last child... same as childNodes[childNodes.length - 1]

.nextSibling
// if using the <ul><li> example, and you referenced the <li> tag, this will get the next <li> tag in the list.

.previousSibling
// as above but the other way round.

.getAttribute()
// returns the attribute in the brackets, i.e. myTitle = myVar.getAttribute("title");

.href
// you can just reference the attribute with the dot operator as you would an object. i.e. myTitle = myVar.href;

.setAttribute("attribute", "value")
// i.e. myVar.setAttribute("href", "/koko/");

.style
// followed by the CSS property, can change the CSS.

.style.color
// i.e. myElement.style.color = "#FF0000";

.className
// myElement.className = "my-css-class";

.createElement()
// creating new elements to add to the html, i.e. document.createElement("span");

.createTextNode()
// creating new content text to add to an element, i.e. document.createTextNode("Text goes here");

.appendChild()
// adding a child element to an existing node, i.e. tip.appendChild(tipText);

.nextSibling

.nodeValue

.removeChild()
// i.e. removeChild(tip)