As you can tell from my images, and from my website workflow pages, I'm a user and big proponent of PixInsight for astro image processing. It's powerful, cross-platform, reasonably priced, and most of all has a large suite of astro focused tools that produce the best possible images from your data. I've bought and tried just about every other piece of astro processing software in the past, and they're now all on the shelf gathering dust - PixInsight does it all.
One comment that new users sometimes have about PI is the lack of a comprehensive tutorial. Although PI now comes with a lot of built-in documentation, and although there is a lot of PI content scattered around the web, it can be a bit overwhelming for users to get started. I've collated several pages with links to PI content, and Harry Page has produced a series of great tutorial videos, but until now there has still been a gap.
Recently, Warren Keller and Rogelio Bernal Andreo have teamed up at IP4AP to produce an ongoing series of detailed PI video tutorials. For those of you who aren't familiar with IP4AP, Warren and Peter Proulx have been producing great astro image processing tutorials for a number of years, as well as providing one-on-one sesssions via the web. The tutorials, which until now have been mainly Photoshop focused, are available online and via DVD, and are highly recommended by many astro imagers. Warren's clear, step-by-step approach has helped a lot of imagers improve their results.
Last July, Warren announced the availability of a rolling series of PI video tutorials. Even though I consider myself an intermediate PI user, I immediately signed up for the series. The cost is $59.99, and it's worth it. Series 1 consists of 22 online segments, starting with a PI overview, and moving through calibration, integration, batch processing, and on to background extraction and deconvolution. I enjoyed the presentation style, and most importantly learned a bunch along the way. Series 2 has just been announced ($39.99) and I signed up for it immediately. Again, it is a rolling release, with new tutorials coming every week or so. Warren states that "In Part-2 of our series, we'll perform permanent, nonlinear stretches, reduce noise, develop amazing detail, and perform many other enhancements using the power of multiscale wavelets transformations. Special techniques such as mosaics will also be covered."
So, highly recommended, and you can learn more at IP4AP.