Where to start ? There's lots of info out there - there's a risk of getting swamped and not finding the stuff that you're after. So, the basics:
Rules / Basics

The rules, regulations and rulings are here
They provide an online coaching tool which is free to register, has lots of drills (you're allowed so many each month for free), there's a free tool to sketch your own drills, hints, tips, etc. Worth a look.
They also provide IRB Rugby Ready - "The IRB Rugby Ready programme aims to support individual coaches, referees, players and Unions in preparing to play the game and with good practice models for physical conditioning, technique, injury prevention and injury management."
Rugby Ready is something your players (and possibly parents) would benefit from also.
Most of the IRB stuff is general - but you will find specific articles on:
Coaching Defence , Counter-attack: decision-making , Playing inside the defence
The RFU site is far less easy to navigate - there's lots of information there but finding it can be an issue - the starting point is the Community Rugby Home Page
Under Referee / Officiate you'll find the Continuum (U7 - U13 Laws) and the
U13 - U19 Law Variations plus other useful info
Under Coach I'm afraid it's a mixed bag - there's some info about training courses but most of the Resource information points you to third parties (who want money !) - there is a Recommended Links page but I'll try and replicate the best ones here.
Probably the best bit (but hardest to find what you want) is the Articles section. You'll find (eventually) stuff on Intro to scrummaging; 3 man & 5 man scrum; Sevens; articles from the Technial Journal; etc.- too much to list here. If there are specific areas you want me to highlight please advise.
There are also loads of Forums if you've got the time !

Simple is beautiful - the SRU site doesn't have information overload - you can quickly find what you're after. I'd suggest going to the Coaching Resources download page. Just 11 documents to worry about - start with Core Skills and work you way from there.
Links to other Unions
