Learn the alphabet and its pronunciation. Some letters sound very similar and you will need to memorize the sound differences so you can then write the words appropriately. Examples include the letters “y” and “ll” and the letters “n” (when followed by an ia) and “ñ.”
Watch children’s TV programs. Most US cities have at least one channel in Spanish. Practice watching and trying to write down some of the words that are often repeated, such as Hello, kids (Hola niños) or See you tomorrow (Hasta mañana).
Find virtual penpals. Focus on Spain, which has the most neutral language of all Spanish-speaking countries. Try to gather a mix of penpals: someone you can chat with over instant messenger and some with whom you can exchange long letters.
Join forums and chat rooms in Spanish. It may be overwhelming at first to try and follow full post ad conversations, but this is a great way to practice your writing and reading.
Read as much as you can. Start with children’s books if that’s all you can manage to understand. Then practice writing similar sentences but replacing the words for others you know. For example, if the original sentence is “The car is green” (el auto es verde), replace it with “the house is blue” (la casa es azul). Even if you need to use a dictionary to do this, it will still help you develop your vocabulary.