VS 2010 An actual dictionary

Alright, for my program I want the user to be able to enter a word, the program searches to check if that word is real, and if it is continues the process. If not, cancels it. There were two options that I thought of, which were:

1. A downloaded set of words which run in the program
2. The program makes a connection to www.dictionary.com and reads from there

However, I have no idea as to where to start for either of these options. Any advice would be most appreciated.

Regards,
Rhys.