There are a lot of great artists here who should inspire and help you.
If you are interested in mapping elements, Neyjour has posted some very nice ones in the mapping elements forum.
And this link will take you to the thread where I have posted hundreds of objects and Items.
Mapping Elements, Starting with Preset Tables and Chairs
If you are looking for traditional mapping elements like mountains and forests, there are some great threads for those as well. Swartzenkruez has some fantastic ones.