Firstly, well done for having a tapestry.
So now, how are you going to look after it?
Here are some pretty good guidelines that are applicable to most textiles and most art forms.
The idea is to keep your art work in the same condition, as when you first saw it.
1.Avoid hanging your work in direct sunlight. All textiles will change over time if left in the sun. Some fibres will discolour, degrade and fall apart. Even natural un-dyed wool will change due to the residue left in the wool.
2.Avoid moisture. Maybe not hang your work next to the bathroom door, the laundry or near where you cook. Moisture is likely to make everything stick to it, like dust and grease (yuck). Moisture may also encourage other changes to your artwork that may damage it.
3.Avoid smells. Your textile will absorb smell. This may not be a problem for you, but where there is smell, there is probably other things that will attach themselves to your artwork. Like smoke, tobacco or open fireplaces. Also cooking smells.
4.Check your artwork from time to time to make sure Arachnae (spider) has not taken up residence in the comfy parts of your tapestry, or any other insects, like moths. Which are diabolical for textiles. If you think there are the kinds of tiny moths living in your house, consider getting some moth traps from the supermarket/hardware shop.
Hopefully, this leaves some where to hang your work!
Assuming you love it, you will have it hanging on your wall for a long time.
Just like other parts of your house it's going to get dusty.
A simple way to clean your tapestry is to take it outside and give it a gentle shake, not like you're some washer woman beating the heck out of it with a broom stick.
A gentle shake.
You will have to be very mindful and careful with your work if it has been made with a thick unspun fibre known as Roving, or Tops (same). This fibre will not take kindly to much friction at all.
The result will be pilling, pulling the fibres, or any other unknowable out come.
Also, experimental weaves, and weaving done by beginners may not have the integrity that plain flat weaves,woven by experienced weavers has.
In these cases, I would recommend a technique that I have seen conservators at the Australian Tapestry Workshop use.
Firstly, if you have a vacuum that has power control- strong and gentle settings, put it on gentle. Then place a stocking, or piece of pantyhose over the nozzle, you could use a rubberband to secure it if you want. Then gently run the nozzle over the surface.
This should do the trick.
If you don't want to do any of these things yourself, you could contact the maker and ask them to clean the work for you.
If you have spilt something on you artwork , like wine or food, I would be very careful of trying to clean it yourself...Textile conservators do exist, and if in doubt, have a look in the phonebook, or contact your local regional Art Gallery, they may be able to put you in contact with the right people.