Buy a dictionary that translates the language into English and vice versa. In the new language, write the names of items around your home such as appliances and food onto note cards, and tape them to the items. This will teach you the names of things you use everyday. Seeing those names will help you memorisze them over the course of the month.
Spend at least two to three hours speaking simple words or phrases of the language out loud. Focus on proper pronunciation. Reading the language is only one step; you must also speak it out loud. Check local colleges and Internet chat sites for places where you can talk with fluent speakers who can help you with pronunciation.
Watch movies in the foreign language. You can either rent movies made in the specific country or, for languages such as French and Spanish, you can insert most of your movies into your DVD player and select the foreign language in the "Languages" option. Watch the entire movie the foreign language, and watch it again with subtitles. It will sound like gibberish at first, but by the second week you will notice patterns in speech and be able to discern what is being said.
Buy a foreign language learning kit or attend classes at your local community college. Some commercial foreign language learning kits are expensive, such as Rosetta Stone, but some are effective. Classroom settings, even for a month, are also very helpful because you get a hands-on learning atmosphere.
Practice, practice, practice. With such a short time frame, the key is to stay focused and work earnestly at the language every day. You should treat this as another job and spend as much time as possible during those thirty days working on the language.