Mrrzy...if you hit the beltway at 66, you would be 'best' going right whic takes you east then curves north towards 'Richmond' (it may say 'Richmond' at some point...which makes no sense, except that the beltway in this direction takes you to I-95 south )...in any case take outer loop, 95/495,(NOT toward Tysons Corner)...go across the Wilson bridge and around until you see N. Hampshire Ave and take 1st exit heading north.

the thing is, it is not very much different either way ...I-66 is almost 180 degrees from the exit you want, so you will hit N Hampshire Ave no matter what you do,(but if you did go 'left' and around on the inner loop, you would take the 2nd N. Hapmshire exit)