Hiragana are used when you can't use kanji, for sound symbolism, particles, help verb, and conjunctions . Hiragana can also be used for adverbs and names for animals and plants. Often you can see them together with a kanji to form a word. Hiragana is used for changing meanings of kanji by adding a hiragana character after the kanji.  Hiragana is also used wherever kanji characters wouldn't be used.

Hiragana can be used to express and write all Japanese words without the use of kanji since hiragana is like an alphabet. If you can't remember the right kanji for a word, you can just spell it out in hiragana. There are 46 Hiragana to learn. In addition to those 46 hiragana there are some hiragana with different pronunciation. Those hiragana have a dot or two small strokes added to them like,
(ha)
(ba)
(pa)
 
 
 

Both Hiragana and katakana are from the beginning Chinese characters. Look at "a" in the table:
( )hiragana "a"
( )Chinese equivalence.  Pronunciation in Chinese is " an".
( )hiragana "i"
( )Chinese equivalence.  Pronunciation in Chinese is " yi".

It is easy to see the resemblance.

Japanese characters are ordinarily written vertically from top to bottom, from right to left.

n	w	r	y	m	h	n	t	s	k
											a
											i
											u
											e
											o

This is an additional table that contains hiragana with voiced sound marks and semi-voiced sound marks, note that the basic structure are the same as abov.
 

p	b	d	z	g
					a
					i
					u
					e
					o

Often this table is displayed in another form, to make it easier to study it for us westerners: ( first row is pronounced "a","i","u","e" and "o". Second row: "ka", "ki", "ku", "ke" and "ko" and so on.
 

	A	I	U	E	O
K
G
S
Z
T
D
N
H
B
P
M
Y
R
W
N