Below is my reply which is essentially a cut and paste so it may lose context in some places, but hopefully others will get some use from it.
Get an understanding of how to use it from JQuery ( $.ajax, $.getJSON etc. ) The Microsoft Ajax libraries are dead and no longer supported. This will be more useful going forward as people start writing web applications with frameworks like knockout. You’ll be presenting an entire API to the client browser predominantly accessed via ajax with JSON being the data format of choice. Taking it to the furthest level your API will be RESTful, embracing HTTP rather than abstracting it as WebForms has for the past 10 years. Microsoft is pushing several stacks for this in terms of OData and the WCF Web API. A lot of people however are dismissing these in favour of using straight ASP.NET MVC and presenting the API through Controllers that only ever return JsonResult. It’s like MVC without the V! No idea where we’ll end up eventually with this one.
You may have already noticed but as soon as you get into using JQuery you realise you need a good handle on CSS selectors so let’s do that one first. You’ll have no doubt in the past been down the road of just randomly editing the CSS, refreshing the browser and hoping the CSS gods are looking down upon you and everything now looks as expected. Unfortunately not a fat lot’s changed in this area but we’re not alone in this camp so there are two OS frameworks called SASS and LESS (http://coding.smashingmagazine.com/2011/09/09/an-introduction-to-less-and-comparison-to-sass/) which aim to alleviate some of the pain experienced with CSS. Do you need to know these; probably not but again it doesn’t do any harm to know they’re there to help.
Apart from the ubiquitous border-radius! Media Queries are the big one here which you’ll hear all about in the same sentence as “Responsive Web Design”. It’s all about adapting the styles used on a web page based on the viewport (device-width) amongst other attributes. The most common usage scenarios are therefore styling for desktop or mobile. MVC 4 is rolling some of this stuff in but also allowing you to easily create media query based or device specific views. Phil Haack did a decent talk on this at Build. Search http://channel9.msdn.com .
Know it, learn it, and love it. You’ll be doing nothing without it. As mentioned up there get your head around the $.ajax API and understand CSS selectors. The best thing I’ve found about JQuery is it’s so ubiquitous now that all you have to do is think about what you want to achieve, type it into Google and append jQuery to the end. Cut, paste and job done. Next level on from that is writing a plugin and then if you’re so inclined JQueryUI which is all about widgets and presentation and finally JQueryMobile which is a mixture of JQueryUI and HTML5 for the mobile devices. I knocked up a half decent iPad version of my LearnAndGame site (see below) literally in about 10 minutes. I’m over simplifying JQuery here as it’s so much more but that’ll do for now.
Get the HTML5 Boilerplate template off the extensions gallery within VS. This shows you some great guidance on website best practice. It’s a bit over the top as a starting point for a site in my opinion but a good reference for learning. Moving on nicely from that also go get the NuGet gallery source from GitHub as this is also a great reference site for MVC development.
** Quite simply the most bonkers and yet wonderful Distributed Version Control System (DVCS) known to man. It makes working in TFS version control feel like seriously hard work.