Here is where we will place some random pronunciation tips. This is by no means exhaustive.
The “o” sound in Japanese is open, and it’s always open. American speakers tend to close their “o” – pronouncing it more like “oh”. This is generally not correct in Japanese. The correct way to pronounce it is closer to “uh”. Listening to a native Japanese speaker is probably the best way to get the correct sound.
The “e” sound in Japanese is somewhere between a long A and a short E. Something a bit like “teh”, but just a smidge closer to a long a. Again, listening to a native Japanese speaker is pretty important for getting it right.
All vowels in Japanese are always pronounced exactly the same. While the “ai” sound is easy to mispronounce, it is actually two different vowels – ah-ee. Though when spoken quickly the sounds are somewhat indistinguishable.
The “n” mora is always its own mora. This is very clear in Japanese songs – they use the “n” sound as a syllable. This can be confusing to non-native speakers.
While vowels are often silent, they still inform the shape of the next syllable. “totemo” and “totamo” (as far as I know a made up word just for the purpose of demonstration) will sound very slightly different, even if the vowel (“e” or “a”) is entirely silent.
Try not to stress syllables. As mentioned in the Pitch Accent page, words are accented by pitch, not stress. You can be expressive with tone, but try to avoid stress as much as possible. This sounds like a small thing, but it really does affect how the word sounds (we will tend to pronounce poorly stressed syllables wrong), and can make it difficult for a native speaker to understand what you’re trying to say.