The way Hiragana works is almost exactly the same as Katakana, except that the characters are different, and that Hiragana is used to write Japanese words. There are some exceptions, however. Sometimes, again to create a "special effect," a writer will use Hiragana to write a foreign word which should have been written in Katakana.
So, anyway, here is the Hiragana alphabet. Look it over, and I'll describe some features of Hiragana.
The first thing you'll probably notice is that Hiragana is more rounded and "squiggly" than Katakana. Apart from that, it operates basically the same. First, you should look over the alphabet and try to memorize it. Have you done that? Okay, then tell me what this says:
. If you guessed "Sushi," then you're right! Sushi, as you might know, is rice and (usually) raw fish rolled up. I personally find it distasteful, but that's just me.
The diacritical marks `` and ° are present in Hiragana as well. They have the exact same effect as in Katakana: K becomes G; S, Z/J; T, D; H, B; and H becomes P with the circular mark °. Adding small Y sounds after -I sounds, and small vowels after some characters creates a diphthong-like effect just like in Katakana. Adding a small "TSU" character right before a consonant sound doubles that consonant sound, just like in Katakana. The double N sound, however, is made by writing an "N" character, not a small "TSU".
Another thing different between Hiragana and Katakana is the way double vowels are written. In Hiragana, a double A sound is made by writing an "A" character; a double I sound, by writing an "I" character; a double U sound, by writing a "U" character; a double E sound, by writing an "I" character; and a double O sound, by writing a "U" character. The last two are somewhat unusual, and there are several exceptions to these rules. For example, 
, which means "Yes," is a double E sound that has two "E" characters.
When a writer has a good grasp of Kanji, he'll usually use Kanji in place of Hiragana. Hiragana is still essential, though, because it is still the only way to represent functional words such as particles, and verb and adjective endings. Here are some important Hiragana characters that are used for that purpose:
This character is an interrogative marker. It takes the place of a question mark at the end of a sentence. So, something like 
"Nan desu ka," means "What is that?"
This character is a subject marker. It directly follows the subject of the sentence. It can only be used in statements, not interrogative sentences. Here is an example: 
"Kore ga o-sushi desu.", meaning "This is sushi."
This character simply means "and." It is used to make compound nouns.
This character is a possessive indicator. Think of it as a direct replacement for an "apostrophe-s". Example: 
"Kurisu no sushi", means "Chris' sushi," or "The sushi of Chris."
This character is a subject marker just like the "GA" character, except that it can be used in any type of sentence. It is pronounced "WA," even though it is the character representing the "HA" sound.
This character is a direct object marker. It is used in sentences like 
"Terebi o mimashita.", which means "I watched television." "Television" is the direct object of the verb "to watch", so the O-particle is needed. This is usually pronounced "O" but historically falls on the W-line, as it used to be pronounced "WO."
That's all there is to the Hiragana part of the lesson. There is much more to Hiragana than what I just covered, so if you really want to use Hiragana, you should pick up a Japanese-English dictionary, or take Japanese classes.