The temperature should be slightly above 20-21 degrees during the day but it can be a bit rainy.
What part of the island to stay depends on what sort of holiday you want. Puerta Del Carmen is the capital and probably the liveliest resort with more nightlife. Costa Teguise seems to comprise loads of large all inclusive type hotels whilst Playa Blanca in the South has more villas and is more family oriented than the other places.
We go at least once a year and stay in Playa Blanca and this year I'm thinking along the same lines as you but am thinking of Fuerteventura next door for the February half term week as it's cheaper