There are many recipes similar to this floating around, some with Velveeta and salsa, some very close to mine but using ground beef...this is the way we like it.
1 large box Velveeta
1 lb sausage - regular or hot, depending on how spicy you like it
1 can original Ro*tel (diced tomatoes and chilies)
chips - your preference
This easily doubles (that's how much I ususally make), or even triples if you have a large enough crock pot.
Cube your Velveeta and put it in the crock pot.
While you're working on this, start cooking the sausage, breaking it apart as you go.
Drain the fat off the sausage and add it to the pot.
Next, pour in your Ro*tel.
Give everything a good stir and turn your pot on low until everything's melted, about 2 1/2-3 hours.
You can turn it on high and it should melt in about 1 1/2 hours(depending on your pot), but you need to check it more often because the cheese will burn on the sides of the pot.
Once it's done, keep it on your warm setting, if you have one.
The cheese does burn on the edges if left too long, but it will last through a typical buffet dinner, or even longer, especially if you remember to go back and stir it once or twice.
We like to use the hot sausage with this and have even added extra peppers when we felt it wasn't spicy enough. If there will be a lot of small children I will use regular sausage, or mix it half and half with hot. I use the homemade diced chilies and peppers that we canned, so mine is a bit more spicy than the original Ro*tel. I think they make a hot version if you really want it spicy.
This is great on regular potato chips, tortilla chips, Fritos (the Scoops work great), or just about anything else. My older brother and my nephew put it, along with almost every other condiment available, on their hotdogs, and many in my family like to top a taco salad with it. They tell me it's good on hamburgers and baked potatoes too. I'm with them on the potatoes, and may try it one day, but I think I'll do without it on my burger.