The Astronomical Unit is a comprehensive website providing extensive guidance and information about astronomy and telescope usage to its users. The online platform presents a plethora of tutorials, articles, and link resources, carefully categorized for streamlined navigation, thereby offering a fantastic resource to both beginners and experienced astronomy enthusiasts.

In terms of tutorials, The Astronomical Unit does a proficient job of progressing from basics to more advanced topics. It expertly educates novices on fundamentals like choosing their first telescope and navigating various eyepiece sets, while also catering to more experienced individuals seeking to delve deeper into areas like the precise polar alignment or color filtering. The tutorials are explained in a straightforward, digestible manner, making it easy for users to understand and absorb the presented information.

A unique element of this platform is its comprehensive glossary, which helo to familiarize readers with technical jargon. This toolkit assists users in understanding complex topics, becoming a beneficial asset for those new or unfamiliar with the more complex terminologies of astronomy.

The website hosts a rich vault of articles and various publications, allowing users to explore different facets of astronomy at their own pace. The range of topics include variable stars, positional astronomy, and different natural phenomena. It also features a section dedicated to pseudoastronomy, debunking theories and addressing popular misconceptions, which can be a great anecdotal conversation piece for astronomy enthusiasts.

A noteworthy feature of The Astronomical Unit is the 'DIY Astronomy Resources', a collection of projects that provide hands-on lessons about constructing Scotch mounts, reflector and refractor telescopes, and even simple dewshields.

The 'Book Shop' section is another beneficial excerpt, offering a carefully curated collection of books on a range of topics such as cosmology, history of astronomy, telescope making and even mythology of astronomy for younger astronomers.

However, the 'Resources' section seems to be limited in terms of non-UK based suppliers. This could potentially leave non-UK visitors feeling a bit excluded.

In conclusion, The Astronomical Unit is a remarkably detailed and exhaustive resource for astronomy enthusiasts. It provides an effective blend of informative content, hands-on projects, and a well-rounded selection of books that cater to a broad audience. Despite its minor constraints, its merit truly lies in its ability to accommodate every stage of learning.