Hi Coleen - I'm a fan of container gardening and I find that giving each herb it's own pot yields a healthier plant with a decent crop. I have chives, lemon balm, mint, bay, parsley, corriander and salad leaves. You will get a crop in a window box, but it will be small.
The other thing that you need to be aware of is the importance of using the correct soil. Don't use Peat or Peat Based. Peat soils are bad for a number of reasons -
1) Bad for the environment.
2) It's slightly acidic (most plants like alkaline apart from heather etc).
3) It has no nutrients.
4) It dries out very quickly and becomes dust-like.
5) Once it dries out, the top layer will become capped - and this is almost impossible to re-wet.
The best type of soils to use are loam-based.
If you are growing from seed, in spring time, use "John Innes No 1" (It's low nutrient, idea for seeds).
John Innes Type 2 for potting on and
John Innes type 3 for transplanting.
(NOTE - don't buy a compost with Added John Innes - it's not the same).
When my plants have come on a bit, i usually repot in my mix of 50:50 John Innes type 2 with a Peat Free compost. Also, you can buy farmyard manure in Woddies. If you have some old compost left over from last year, you can add this to improve it and it also adds a good balance of nutrients.
Happy gardening.