If you know how to clean a dove, quail, or other small game bird you know how to clean a snipe. There are several ways to prepare them for cooking. Some recipes allow for several options in how birds are cleaned so that decision will be up to the one doing the cooking.
The more traditional way would be to leave the carcass essentially whole, removing only the head and neck, wings, feet, and feathers. At this point you can either draw them or not. Are you familiar with the term "drawn" when referring to dressing game? To draw a bird means to remove the entrails. There are a number of recipes requiring a bird that has not been drawn but I have never cooked mine that way. You will find this type of preparation more common on other continents but there are some people in North America that also clean and cook their birds with the entrails intact. The other decision to be made when cleaning this way is whether you are going to skin your birds or pluck them and leave the skin intact. No matter how I clean and cook my snipe they are always skinned.
The way I dress most snipe is to remove the breast only. If you want to gnaw on legs that is fine but I don't. The only time I don't cut out the breast is when I am going to stuff the cavity. In the end it is still only the breast that gets eaten. When I am going to remove the breast I don't pluck the bird. I grab the skin at the center of the breast and peel it away in all directions. Then I insert my thumb through the thin flesh at the bottom of the breast. I run my thumb down one side, separating the breast from the ribs and the rest of the carcass. Then I do the same thing on the other side. Now the breast will only be attached at the shoulders. A snip at each shoulder with a pair of game shears and the job is done.
The other option is to remove the meat from the bones. I don't do this with snipe but I have done it with ducks. If I decided to debone a snipe I would only use the breast and maybe the thighs. I would start the same way I do when I remove the breast, but instead of cutting the breast off at the shoulders I would just cut the breast meat off each side of the breast bone. Then I would peel the skin back at the top of each leg and cut the tiny bit of meat away.
One other decision to be made is whether or not you want to use the giblets. I don't eat them but I do remove the gizzards. I cut and clean them the way chicken gizzards are done. I examine the contents and then I cook them. I don't really know how they taste but my dog likes them just fine.
I don't clean my birds the day they are shot. They will rest for two or three days in a refrigerator prior to being cleaned. Some people raise their eyebrows when they hear that but meat should be aged. I have a friend that forgot about some dove he put in his refrigerator and it was three weeks later before he remembered them. He will tell you those were the best dove he has eaten. I have snipe in the freezer year around. To keep them fresh I use a vacuum sealer. I have a Foodsaver brand sealer but there are others that work just as well. Supposedly they will keep food fresh for 2-3 years. I have not tested mine for that length of time but I can vouch for it keeping things fresh for up to one year. When I take my snipe out of the freezer I remove them from the vacuum bag and thaw them in water in the refrigerator for a day or two. When food has been stored under vacuum you should break the seal when you start to thaw it. Otherwise the vacuum pressure will draw the moisture out as it thaws.
Even if you have never cleaned a bird before this should get you headed in the right direction. I didn't have anyone teach me and I have done alright dressing a few thousand snipe over the last few decades. If I can do it you can too. When you are finished your birds will look just like the ones below.