The Lake of Annecy surrounded by mountains is amazing at all seasons, you can enjoy it by boat, bike or car.
With a car, I will recommend you to start from Sévrier (as the traffic Sévrier/Annecy can be quite bad sometimes), go through St. Jorioz, a quick stop in the center of Duingt (a little walk to the castle) then maybe a swim or lunch in Doussard.
After visit of Talloires, my favorite village by the lake, follow the parking signs then walk down to the port. You will find the Auberge du Père bise (Relais Châteaux and one Michelin star), next to it you have a little shop who sell goodies. The Abbaye de Talloires where Paul Cézanne stayed for a summer and painted "Le Lac Bleu".
Then if you are lucky and there are no clouds, drive up to Col de la Forclaz (Montmin) which is 1157 meters high, it is about 20 minutes drive from Talloires but the view is fantastic! It is famous for paragliding lovers! You can walk up hill for 15 minutes to reach the paragliders departure place which is a lovely spot to take photos or have a picnic.
Finally, you can make you way back to Annecy going through Menton St Bernard and Veyrier du Lac (maye stop to see the Castle of Menton, the best spot to take a photo is to take the road going to Alex on the right when arriving in Veyrier).
If you do not have a car, I will be happy to take you with my taxi for a tour of the lake, if you want an english speaking driver, please book in advance!