Hello, Marzi. I would highly recommend the following self-study programmes.
Audio Programmes: Mitchel Thomas Method, Pimsleur Method.
Books: Assimil's Spanish with Ease, Routledge's Colloquial Spanish and Teach Yourself Complete Spanish.
Computer Programs: Tell Me More and Rosetta Stone.
If you have further questions on how to go about the learning process when studying by yourself, you can text me any time.