UKH

Im off to Nepal in a couple of weeks to do the Gokyo Lakes and Everest Base Camp trek and using a Nikon D5100 with the kit 18-55 lens. Any advice on filters needed if any? 

You don't "need" to take any filters.  You also don't say what you interested in taking photos of.  If I was lucky enough to be doing this trek, I'd take a UV filter for sure (to prevent blue snow colour cast), a circular polarising filter, and if taking sunsets/sunrises, I'd take graduated ND filters of different strengths.  I'd also take a tripod for my landscape photos.  If I could only take one of those things, I'd take a tripod.  Shoot in raw and you can edit as much as you like to mimic the effects of the filters.  Good luck with your photos and have a great time!

Tom

If you plan on doing time lapse then an ND Filter would help give good results by creating motion blur and a smoother finished product.

I'd say a Circular Poleriser would be your best all-round choice for vibrant deep saturated colours fit for any travel Brochure.

If you are planning on any video then an ND Filter will help with wider apertures in daylight for shallow depth of field.

A UV filter would be a good idea to protect your lens glass from scratches. However a UV Filter will do nothing else because a camera sensor isn't affected by UV like traditional film.

If funds can stretch that far, and if your camera has a kit lens, may I suggest upgrading the lens.

You probably won't be going back and a sexy quality lens will give you images to drool over for years to come.