I'm taking a test this June that requires the know-how to write a basic Japanese essay. Nothing too advanced - it's aimed at people learning Japanese for around 3 years. (GCE AS Edexcel Japanese for those interested.)

I've done the same qualification for French, and if there was one thing that helped me, it was the fundamental essay phrases given in the study guide. After pounding them into Anki, a month later I had them down cold.

Does anyone know of a similar list for Japanese?

I don't mean phrases like "The national economy has ground to a halt" or "Contrary to the opinion of the uneducated masses" - just very simple, absolutely essential basic essay phrases like "On the other hand...", "In my opinion..." or "I don't agree because...". Except with Japanese

Absolutely massive, huge, lifesaving ものすごくものすごい thanks to anyone who could point me in the right direction! I really don't know where to begin looking for this one... Google is being no help at all

There are a bunch of books aimed at foreign students at Japanese universities covering how to write reports and make presentations. Some are at an elementary level and give the kinds of expressions and connecting phrases you're looking for. If you search something like 留学生のために　in Google books or Amazon you should see a few and can follow the listed related books.

One is available for download from a dodgy site with viruses. (pm me if you want)

Another option might be books for Japanese school kids learning how to compose (作文). There are plenty of those books and some are useful tools for learning to write. But perhaps not ideal for your situation: the explanations aren't in English, the phrases aren't listed and the themes aren't as adult/academic.

btw, I'm assuming you're not talking about the traditional Japanese essay structure (which differs from what we're taught in North America). If you need that, I recommend Senko Maynard's book called something like "Intro to Japanese Discourse" (there are links in the forum).You can read the relevant section on Google.