Maybe projecteuler.net ? You don't need too much skill in programming to solve the tasks, but you'll have to think about the problems (oh, and a bit mathematical knowledge helps, cause that's where the problems come from - though you can usually just brute force your way through).
If you got the first problem you should be able to get at least the first ten. Number 2 isn't very hard at all. First just make an array to store all the numbers in the Fibonacci sequence. To create the next number add the previous two elements. In pseudo code your general program should look like this:
1 2 3 4 5
initialize the first three elements of the array with 2, 3 and 5
while the current element is less than 4 million
make the next element the sum of the previous two elements
if the new element is even
add the new element to the total
As for the third problem it's very difficult to brute force it so you'll have to find a more efficient way of finding the prime factors of a number. I can help you out with that one too if you want me too, but I don't like giving away answers so give it a try first.