All I can seem to find are World War 2 accounts and I'm interested in the Nara period into the Heian period. And maybe some other books about the feudal era. Geographically my university doesn't have any professors that are familiar with this and I want to get a jump on learning this material before starting to study it. Many thanks in advanced!
If you are mostly interested in ancient Japan, I would recommend picking up translated editions of Nihon Shoki and Kojiki. These are primary sources; chronicles of ancient Japan and how the Japanese people and polity came into being. BH Chamberlain did a good translation of the Kojiki a few years ago, and that edition has commentary that might aid you. WG Aston also did a translation of Nihon Shoki which he titled Nihongi: Volume 1. Personally, I don't like his translation, but it remains one of the better English versions.
Now, if you are looking to learn about other Asian cultures, there are a few other primary sources I highly recommend. For Korea, the Samguk Sagi and Samguk Yusa are twelfth century retellings of the history of the Three Kingdoms period in Korea. Unfortunately, as far as I know only fragmentary translations into English exist, the best of which can be found in Sources of Korean Tradition: Volume 1, Earliest Times through the Sixteenth Century by Peter Lee, et al. Again, the added commentary is very helpful.
For China, there is an abundance of primary sources from ancient times. For a historian, however, the most important is the Shiji, the records of the grand historian by Sima Qian. This was produced during the Han dynasty and records the rise and fall of Qin Shihuang as well as some aspects of earlier history. Burton Watson produced a translated version in the early 1990's, however its specific title eludes me at the moment.
About Mongolia, the end all and be all is The Secret History of the Mongols. The best edition right now is Igor DeRachewiltz's massive two volume translation and commentary The Secret History of the Mongols: A Mongolian Epic of the Thirteenth Century. I am using it for my current project, and it is invaluable. I recommend reading it even if you don't particularly care about Mongol history because it is simply a fascinating and beautiful piece of literature.
I've given you all primary sources because I believe you should start to form your own opinions based on the sources before delving into the opinions of others. I personally don't study Japanese history much before the Imjin War of 1592, and it sounds like you are interested in the period before that. Maybe some other historians could help out with the secondary sources on the period?