First, anyone who is or wishes to be a practicing musician should be capable of distinguishing and identifying ajnas by ear. You can polish up those skills by visiting the Beginner Track and by spending time on the Basic Ajnas section of the site, where you will find audio samples of all of the most important ajnas used in the maqam system. If you need to brush up on definitions, visit the Glossary, and if you need more clarity on how to read the content on this site, visit the How-to section. If you are interested in some of the new theory insights presented here, consult the "Jins Baggage" section and the "Previously Unnamed Ajnas" section, which will also help clarify how best to parse the melodies you hear.
I would advise musicians (or those wishing to develop into arab musicians) to focus primarily on whole songs, and follow the whole song analyses presented either in the section of Analyses by Maqam or the List of Songs. Many of the songs on this site are among the most famous songs of Arabic music, and any musician should know them intimately: Ah Ya Hilu , Ghannili Shwayya, Muwashshah "Jadaka-l-Ghaithu", Muwashshah "Sihtu Wajdan", Muwashshah "Ya Shadi il-Alhan", Nura Nura, Samai Bayati il-3ariyan, Ya Maal ish-Sham, and Zeina Zeina.
You can use the analyses on this site as practice tools to learn the songs by ear. In other words, because it is usually easier to learn songs by ear by breaking them up into smaller chunks, and imitating and repeating those chunks, you can use the segments I've divided by jins as your "practice" segments--which in and of itself will emphasize your sense of the ajnas. Of course, some of these segments are too long for that, and will need to be broken down further; and on the other hand, sometimes the division between segments is melodically awkward, because a modulation has happened in the middle of a contiguous melody. I've provided the complete recording of the songs on the individual song pages, so you can use those as well, when the jins breakdowns are not as practically helpful.
Once you have developed a large enough repertory by ear, you should naturally start, on your own, to come to the conclusions presented on the "Common Pathways" section of the site; in fact the content presented in that section is meant to reflect the basic acquired knowledge of all practicing musicians. Musicians with some level of experience should probably start with that section to make sure they understand what is presented there, and that it jives with their experience. And although the "common pathways" of Maqam Rast and Maqam Bayati are the only ones explored in that section (I selected those two maqamat to explore in detail on this site, because of time and space constraints), an experienced musician should understand that everything he or she knows by ear reflects a common pathway in some maqam or another--and that the pathways demonstrated by the songs in other maqamat included on this site are also common pathways, shared by other songs in those same maqamat (except for the rare cases illustrated on the "Unique Pathways" page).
The eventual goal of the musician, in working toward expertise, is to develop as large a vocabulary as possible of the "common pathways" of all of the maqamat used within the maqam system. Most musicians do this unconsciously and naturally, simply through the acquisition by ear of a large body of repertory--in much the same way that nearly every human being learns the common words and grammatical constructions of the language they speak simply by acquiring by ear a large body of vocabulary and sentences in memory. In other words, the common pathways represented here are also intended as representations of the common neural pathways in the brains of expert musicians who acquired Arabic music by ear. So you really don't need this site at all, as long as you dedicate yourself to listening and learning as many songs as you can by ear; but this website may useful to the extent that it has some explanatory power in describing the structure of that learning.