There are plenty of websites that offer Spanish courses from basic to intermediate level. You can avail of free courses or purchase Spanish modules and software available online. There are also books, module, audio tapes, dictionaries and other materials available in the market to help you with your Spanish lessons.
The biggest problem you will encounter trying to learn Spanish from home is that there will be no one to monitor your progress and guide you. You will also have no one to practice conversing with. The best way to learn any language is to constantly practice it and learning Spanish at home means that often, you will have to practice by yourself.
Fortunately, there are many methods by which you can learn and practice Spanish at home. You can start by reading whatever Spanish literature you can get your hands on. Just practice reading everyday and soon you will find yourself able to speak the language fluently. Practice leading aloud so you can hear your voice. You might become self-conscious about reading aloud but you have to practice until you become comfortable with the language.
You must also try to listen to as much Spanish audio as you can. You can use the audio materials provided by websites and you can also download Spanish music and other materials which you can listen to while in your car, cooking, or doing some house chores. This way you can learn to speak Spanish in the right context and with the right accent.
You can also watch Spanish telenovelas or soap operas. The soap opera can be your daily tutor and you can follow the story line and learn the dialogues. Watching Spanish movies with English subtitles can also help.