Getting the foundations for a garden building correct is very important. The foundations must be level and firm, drainage is also an important factor to consider. Also position of the building should be well planed so as not to be obtrusive, whilst allowing easy access with large items. A corner of the garden is the most obvious place for a shed but remember to allow enough room to get around all the sides to treat the timber. The best type of base for any garden building is a concrete base laid on hardcore, but this can be expensive and difficult and a professional builder may be required to do the work for you if your are in any doubt.
The two easiest and still very effective types of bases are a slab base or a treated timber frame base. Please click on the links on the right for guides on creating these types of bases.