The best advise for a newcomer is don't spend a boat load of money on gimmicky equipment found on the internet.. most of it is way overpriced and it's usefulness is at times very dubious. The people who made the most money during the Gold Rush days were selling equipment to miners, not mining themselves.. it's the same today.
Take for instance "Clay-B-Gone". It works, it will emulsify (liquefy) red and blue clay, however it's expensive. I learned a neat trick from an Archeology friend of mine at Tulane University as to how they liquefy clay. All you need is a free ion of hydrogen and a free ion of fluoride. Find a one gallon milk jug in the trash. Wash it out and fill it with water. Squirt in some fluoride tooth paste and pour in a small bottle of hydrogen peroxide. Shake the jug, if it turns blue like the sky, the mixture is perfect. Cost ? A little bit over $2 dollars a gallon. This stuff will work as good as, or better than "Clay-B-Gone".
Building your own sluice box will generally result in better equipment than the pricy sluice boxes you'll find on the internet. Whatever you build, include "Razor Hog" rubber mats, they're the only thing I'd buy off the internet.. They actually work !
In fact, for prospecting purposes.. you're best off with nothing more than a "Poop Tube" sluice. Go to a Walmart garden department, or Ace hardware and buy three foot of 6 inch wide flexible plastic ribbed drainage pipe. Cut it in half and glue it into same size thin PVC pipe if you desire a more rigid design. Cost minimal, weight minimal. It will perform as well, or better than a $250 dollar Keen "Stream" Sluice Box.