Can I pick peas and freeze them in their pods straight from the garden?
What kind of peas are you referring to? Most all peas and beans have to be shelled first. Also, peas and beans, pretty much any vegetable really, has to be blanched before freezing to destroy any bacteria. If you aren't experienced with freezing fruits and vegetables, I recommend you go to the Ball website. They make canning supplies and the website has great information about preserving vegetables.
Blanch first to preserve the color and flavor. You can use a microwave for blanching. Moseley3 gave you the best advice. If these are a snap pea for pea pods, you won't need to shell, but you want them ready to cook. I never add anything to fresh vegetables so I am not limited when I use them. Another trick is after you have chilled them from blanching is to put a meal's worth in cheap plastic sandwich bags, seal, then then put those bags in a quality freezer bag. Be sure to label the big bag as to contents and date.
Shell the peas first. To blanch, put the vegetables in a small amount of boiling water (although I used my metal vegetable steamer to preserve the vitamins) for approximately 2-3 minutes. Then you want to immediately put them in an ice bath of water (water with ice cubes in it) for 2-3 minutes to stop the cooking process. Drain very well, layer the peas on a cookie sheet and put into your freezer for about 10 minutes. Then put into freezer baggies. Suck out the extra air by using a straw and seal tightly (this will prevent freezer burn). The quick freeze will keep them from becoming one big clump in the freezer bag so you can use small amounts at a time, should you wish.