To find the total pounds of snacks Jenny bought, you need to add the weight of the peanuts and the weight of the raisins together.
Jenny bought 5 pounds of peanuts and 4.08 pounds of raisins.
So, the calculation is:
\[ 5 + 4.08 = 9.08 \]
Therefore, Jenny bought a total of 9.08 pounds of snacks.