Use newspapers or books and read sentences aloud to yourself. This will help you to hear the Spanish language around you. Try using television programs on Univision, which is a public access channel. You can also use recorded music downloaded from iTunes or bought from stores. Often, artists that sing in both Spanish and English will provide copies of lyrics in both languages.
Listen to the Spanish spoken on your program or CD while looking at the lyrics in front of you. If you're watching TV, you can turn the subtitles on and read them while listening. Eventually, you will be able to turn spoken sounds into syllables and words.
Listen for the accent patterns in other peoples' speech. You can use the second-to-last-syllable rule to try and decode the length of words and which syllables belong in which words.
Keep in mind that Spanish is spoken with different inflections in different countries. Slang also changes from place to place and country to country. For example, para sometimes gets shortened to "pa" and often in words that end in --ido, the "d" gets dropped, so the sound ends up sounding like "io" instead.
Listen for the definite articles in words, such as "el," "la," "los" and "las." This can clue you in to listening for specific nouns. It will also help you learn the correct gender of those nouns.
Listen for over-emphasized accents in sentences. Often, when an accent sounds like it is pronounced too strongly, it denotes a word with an accent written in.