As someone who taught himself Spanish and French, I would say this:
Get an english grammar book that has a lot of written exercises and try to do them for an hour per day. Try to get one that is written by someone who speaks English as their NATIVE language. There are a lot of crap language learning books filled with mistakes that make students sound "foreign."
Get a relatively easy to read book and an English-"Your native language dictionary" Look up all the words you don't know. At first this will suck, because there will be many words you don't know, but in time your vocabulary and grammar will vastly improve. Don't feel silly if you have to start out with a kids book. I started reading children's stories and ended up reading Spanish translations of Tolstoi.
Also, when you feel ready for it, buy a quality english only dictionary. Relying on an English-"Your language" dictionary will limit your understanding of the nuances of many words.
If you can, find some one who speaks english very well and practice speaking with them. Maybe you can do a language exchange online?
Good luck!