I used this dictionary for 2 years of highschool Russian and it was irreplacable. It is relatively up-to-date so you will find technical terms in it and the appendixes in the back are great. Most of the other people in my class liked it too. Its very small size (about the size of an index card) made it handy to carry around but sometimes the small type was slightly hard to read.
From Amazon.com
...irreplaceable
What is more important then learn the language? If you agree with that -buy the book! It's execellent!.....Keep it next to the computer! Have few of them....