The first ever manure I used in my garden was from sheep, and not only is it a great fertiliser, it is also a great mulch as well. However, some precautions must be taken to ensure that it just doesn't lead to a weed infestation.
First off, the garden that the manure is used in is four raised garden beds where I basically just dumped it on the top. Importantly, the manure that I used was from an old shearing shed, so while it is free and plentiful, it hasn't been composted.
To get the best benefit from the manure, I found that having it on the garden bed about two weeks before planting allowed the topsoil to retain moisture and the soil became far more friable. Over the season it decomposes further, becoming another layer of topsoil.
Because of the age of the manure (likely 15 years plus) it is a very cold manure, so I am unsure of the actual nutritional benefits of it. However, the manure that you would buy from a garden store is high in nitrogen and many other trace minerals. The way that I use it also makes it a great source of organic matter.
The one problem that I have had with my manure has been that it can cause some weed problems. The main cause of this in my case has been a mix of it never being composted and seeds blowing in under the shed, contaminating it. To fix this problem, the manure should be used in tandem with a lasagne system, placing straw on top of it. This stops any weed growth while still getting all of the same benefits from it. The only downside is that it requires far more labour.
I have found sheep manure to be a highly beneficial tool in my garden, and I am sure that if you try it the same results can be reaped. Happy gardening!