Photoshop-plugins

Size Marks PS - This script converts rectangular marquee to labeled measurement mark.

Random User - Easily drag and drop random users into your PSDs.

HTML/CSS/JS

Bootstrap - Most popular web framework.
Magnific Popup - Simple litbox with WP plugin.
Simple Parallax Scrolling - is a dirt simple parallax scrolling effect
Page scroll to id - simple navigation scroll plugin for landing pages.
Codepen - Many intresting code.
Waypoints - triggers for scroll.
Animate.CSS - cool js/css effects for text.
MixItUp - animated effects for sorting and arraging
Card Fun [CP] - Preaty CSS3 Gallery.
Crafting better [CP] - Adaptive image gallery on CSS.
CSS3 Slider [CP] - Responsible CSS3 slider.
CSS Slidy [CP]- Responsible CSS3 slider with caption
3D Flip [CP] - 3D Flip CSS3 image gallery.
Before/After [CP] - Before and after image comparison.
Easy Masonry [CP] - CSS gallery with highlighting
Ken Burns effect [CP] - CSS/JS script for Ken Burns Effect.

Cliparts

Linea - Preaty light icons set.
Stocksnap - Free photo stock.
Designuourway - Links to free photo stocks.

Manuals

How to create wordpress theme - video manual with sources.

Learn X in Y minutes - short manuals on many languages.
PHP the right way - short documentation on php.
JS tutorial - good tutorial on JS.
AngularJS - russian manual.
JQuery book - JQuery for beginners.
HTML Academy - html/css/js learning

Great sites

PacToCoffee - intresting landing page.
Food sites - good sites about food.
Hello brand - intresting portfolio with landings.
AWWWAWARDS - The awards for design, creativity and innovation on the Internet.
CSS design awards - an international web awards platform.