You need to place your beds where they get adequate sunlight (6-12 hours). I personally like touse my beds as landscaping additions, when possible. From the looks of your yard, I suggest to the left of your house as you face it. Southern or eastern exposure is always good. The trees on the other side and in the back may rob your plants of some of their needed sublight. I suggest that you create a plan similar to the one I am attaching so that long-term you can plan what you want to plant.

I agree with CharlieBoring. And I always recommend that people make a garden plan ahead of time. This will help you plan the space out so you can be sure to have different things in bloom throughout the Spring and Summer. This also helps you to avoid spending money on plants you don't need/have space for; you planned it out ahead of time, so you know exactly what you are going to purchase before stepping foot into a garden center. I used the Suncast space planner last year to plane my new garden and it was great. Best of luck. Enjoy your new garden!

A little late here, so you may have built your beds already.

It looks like you have a patio out back, so it may be nice to admire your beds while you sit or eat outside. I would keep the beds out of the winter shade caused by those southern trees. Even if you're not growing in the winter, you want the soil to warm up early.

I attached a few options. One would be some beds SE of your home. The other would be flanking your driveway. If you make an attractive bed with nicely constructed cedar/redwood or stone, then it will be pretty nice to walk by that every day. Plus, if you walk by your plants twice a day you are more likely to catch issues as they arise.

Good luck and let us know what you do/did.

Matt