Here's my page of links to useful landscape information and other random stuff.
Here is my Flickr photostream, featuring before and after pics of gardens I've done as well as other random plant-related stuff. I've just now begun uploading stuff after a few years' absence.
Here is my blog. I haven't updated it for a few years but plan to soon.
Texas A&M Agrilife Extension Service's Webpage is the most comprehensive resource for Texas gardeners. That it is specific to our climate makes it my first stop for most of my questions. It has a truly amazing amount of information; so great it can be overwhelming. Use the search tool. I plan to add additional direct links. Like, here's TAMU's Texas Tree Selector; it will help you make good tree choices.
Native Plant Database at the Ladybird Johnson Wildflower is a great place to read detailed information on native plants. Look up plants by scientific or common name, or by various criteria such as deer-resistance or butterfly attraction. Mr. Smarty Plants has probably answered your exact question before.
Dave's Garden is a really great place to read about gardening and read comments about plants from gardeners everywhere. I really like their freeze dates by zip code page; a much more nuanced answer to the first frost/last frost question.