Basically buddy if you do physically want to learn how to read and understand Japanese I would start with Hiragana. I might be rephrasing a little of what others have said but I think on very first introductions the absolute simplest and easy to understand explanations are the best. So here we go:
Japanese compromises 3 sets of "alphabets". This will be the first and only time I will use the term alphabet purely to help you visualise what I'm talking about. Strictly speaking the 3 sets are not alphabets because they consist of syllable sounds and vowels rather than individual letters like in the English alphabet. Because of this they are refered to as syllabaries or character sets. I think its best to just get you started on Hiragana first.
The first character set is called Hiragana and you can see a chart here:
Free Japanese Lessons - Hiragana - The Japanese Alphabet (Hiragana Chart) - Learn to speak the Japanese language online for free!
As you can immediately see Japanese appears to miss a lot of letter/sounds from that of English such as C, X, L, F, Q, V. This is simply because Japanese uses less sounds than that of English and the apparent missing letters/sounds can be produced roughly through other syllables sometimes.
Basic Hiragana is divided into 5 vowels the same as English A, I, E, U, O. It then has 70 basic syllables that represent sounds, like banana is ba-na-na 3 seperate syllable sounds rather than 6 individual letters. There is also a special character which corresponds to the n/m sound and whether it is an N or an M depends upon the context of the word but that isnt immediately important just yet.
Theres no perfect way of learning Hiragana just be structured and take your time. Learn 5 characters at a time. Once you can write the 5, pronounce the syllables they correspond to and visually identify what each of the 5 characters mean then you can move onto another 5.
Lets now talk about the 2 little symbols that appear in the top right hand corner of some kana that confuse a lot of beginners. They look something like this:
ご - 2 little strokes in the corner.
ぱ - A little circle.
The 2 little stokes are called Dakuon and the little circle is called Handakuon. They are basically there for converting the sounds of syllables. Lets look at the row of kana that corresponds to "H sounds" we have:
ha は hi ひ fu ふ he へ ho ほ
You'll notice "hu" is actually "fu" but we'll get onto that later dont worry. First of we see we have our H line of syllables by adding the 2 little strokes in the corner we can convert these H's into B's and they become:
ba ば
bi び
bu ぶ
be べ
bo ぼ
When you first start learning you'll find them profoundly annoying and will mix H's and B's up on occasion but this is perfectly fine and normal you do adapt to it very quickly though. The conversation between the H's and the B's we've just seen was because we added those 2 little stokes in the corner - The Dakuon.
Now we'll look at the other little symbol that can inhabit the top right hand corner, the little circle which we call Handakuon.
pa ぱ
pi ぴ
pu ぷ
pe ぺ
po ぽ
As you now know you can convert H into B but by adding the Handakuon you can turn a H or a B into a P syllable. Luckily Hiragana only has one Handakuon conversion which is H/B syllables into P. Dakuon however has several. Using the same rules as above I'll quickly show you the Dakuon conversions for the other syllable lines.
K becomes G e.g. ka か ga が
T becomes D e.g. ta た da だ
S becomes Z e.g. sa さ za ざ
Theres no easy way to learn which line of syllables converts into another they simply need to be learnt and memorized but luckily theres only 4 (Including the H-B we did earlier).
Now remember earlier when we looked at the H line there was no syllable for "hu" and it instead read "fu". This is very annoying at first but its simply an exception you need to learn when reading and writing in Hiragana. I'll give a brief list of the other exceptions:
si - shi
ze - ji
ti - chi
tu - tsu
di - ji
du - zu
This may seem like a lot of exceptions to the expected syllables in each line but bare in mind you'll be learning 5 at a time so will only have to learn 1 exception at a time. They are very easy just handle them one at a time just like your 5 characters and you'll be fine.
Theres also an "expanded" Hiragana list which corresponds to additional syllables and syllable + vowel combinations. Just learn the basic chart first then come back and we can tackle the expanded chart. Theres one rule for the expanded chart you need to learn.
The first letter sound of the expanded characters corresponds to the 2nd syllable from its line on the basic chart e.g.
nyo will always be にょ - ni に being the 2nd character from the N line.
