We can share several resources below to help you narrow-down a list of candidates for these areas. Whichever species you prefer, we suggest using a mixture of species in general, as diverse plantings have better resilience in the face of future pest or disease outbreaks, or occurrences of unusual weather that cause plant stress or damage. Plus, species diversity tends to provide greater support for wildlife and also adds aesthetic interest year-round.

Conditions to keep in mind when selecting candidate plants includes the unpalatability to deer (as you mention; just realize that nothing is deer-proof), how much summer sun they'll be exposed to, and the relative wetness or dryness and drainage of the soil in these areas. You mention the sites face south, which usually has a hotter, drier, full-sun exposure, but nearby trees or structures can alter that sunlight level, so we didn't want to make assumptions. While drainage issues can sometimes be mitigated, it's always simplest (both for yourselves and to lessen any stress on the plants) to work with the conditions present rather than trying to change them to suit certain plants. Fortunately, there are a decent number of native species that can handle either drier-than-average or more poorly-drained soils, both among perennials and shrubs.

Planting for birds can encompass both direct food sources (the seeds or fruits/berries the plants produce) as well as indirect (blooms or foliage that draw insects which the birds consume, which can include pollinators like bees, wasps, beetles, flies, and moths). Providing shelter from their own predators and the weather, often by means of densely-branched shrubs, clumping grasses, or evergreens, is another element to gardening for birds to consider if space allows.

For areas you wish to plant in stages, or areas needing erosion reduction while the plants mature and fill in, you can mulch bare ground with either fallen leaves (leaf litter, either whole or shredded into smaller pieces with a mower or weed-whacker), bark mulch, or arborist wood chip mulch. The latter of the two mulches is preferred by some horticulturists in terms of potential long-term soil health benefits and cost per volume, but sometimes is only available in large quantities that you may need to share with neighbors or other gardeners in order not to be overwhelmed. (Tree-care companies dumping loads of wood chips usually don't want to travel to more than one address.) That said, a surprising amount of wood chips can be used in a modest-sized yard to mulch various beds or walking paths, so accepting an entire load might actually be a non-issue.

Here are some reference materials (they will overlap a fair amount) for native plants in general or bird-related selections:

• Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay Watershed [PDF]
• Chesapeake Bay Native Plant Center - essentially a web-searchable version of the above resource, where you can browse by site condition or search specific species
• Native Plants of Maryland [PDF]
• Landscaping with Native Plants (link to PDF download)
• Native Plants for Northern Virginia (still applicable in central MD)
• Recommended Plantings for Migratory Songbird
  Habitat Management
• Audubon native plants database
• Native Birds Need Native Plants - MD DNR (a handful of plant recommendations)
• Chesapeake Bay Landscape Professional - organization where you can search for designers and project managers who are trained in sustainable approaches, in case you want project help or a resource for future on-site consults; use the "find a pro" link for the directory search
• Maryland Native Plant Society list of native plant vendors (not an exhaustive list, and more suppliers might be found online)
• deer-resistant native plants (not an exhaustive list, and regional deer lists sometimes conflict with each other, but some of the more reliable options)

Here are some tips for plant selection, in case they're not detailed in any of the resources above:

• Many shrubs that produce berries that birds enjoy are dioecious, which means they produce male and female flowers on separate plants. Female flowers produce the fruit/berries/seeds, but only if pollinated (male flowers provide pollen that wind or insects move to female flowers).  Any given year, weather that's too cold or rainy might lead to poor pollination that year, so realize that berry production might not always be excellent. While a 1:1 ratio of male-to-female plants is not necessary for good pollination (3:1 or even 5:1 or so can be sufficient), be aware of plant candidates that will need a pollinator. Occasionally, certain selections will be capable of producing fruit without pollination, but they are in the minority. Plant groups that generally need to have pollinators accounted for include Viburnums, Hollies, Bayberries, and Junipers (Eastern Redcedar).
  
• Cultivars are selections of a species that have unique characteristics, and are then propagated in a way that clones them to preserve that genetic identity. The use of cultivars when using native plants is not a black-and-white issue, and while giving preference to the straight-species natives may be best ecologically, sometimes cultivars have improved resistance to disease or traits that don't necessarily detriment their interactions with wildlife. Studies comparing cultivars to straight-species have shown mixed results, with one group sometimes supporting more wildlife than the other. The main caveat when using non-cultivars is to keep in mind that the genetics will be a bit pot-luck, meaning that if you are relying on a male-female pairing for dioecious plants, you won't be able to tell which plant is which until they are old enough to bloom. (Even then, sometimes distinguishing bloom types can be very difficult.) If you have room to plant several individuals of the same species, you'll probably wind-up with at least some of each sex in order to get decent pollination and berry production.
  
• Make sure you account for mature plant size when planning planting locations, especially for shrubs or small trees. While some species are very tolerant of pruning to restrain their size, doing so can interfere with flowering (and therefore berry production).

If you have specific questions about the suitability of certain plants for either wildlife value or the site conditions, feel free to ask follow-up questions. There are too many plant options (fortunately!) to list them here for you, which is why we're sharing resources that we hope are helpful, though we recognize that list might be overwhelming at first glance.

Miri