The 70/75-300mm zooms in the Canon and Nikon bundles are rather limited lenses--they're heavy, slow, and having no image stabilization/vibration reduction, they're difficult to use in anything short of bright sunlight, especially handheld. Could be somewhat of an advantage for the dedicated student perhaps, as creatively overcoming their limitations helps you focus on technique (a piece of kit is only as good as the photographer using it) but a lot of the time they're dead weight. Not to say they're incapable of taking an impressive shot now and again, but it's worth bearing in mind. You might want to shop around for a kit with just the kit lens instead and apply any savings to picking up a prime lens in the 85-100mm range (Canon's 85mm 1.8 is around 350US right now), which would be more useful (and far more satisfying) for chasing around kids and pets. Or at the least go for a Canon or Nikon bundle with an IS/VR telephoto (usually 55-200mm or thereabouts).
Another item you might want to try to fit into your budget is a separate flash unit, preferably one with bounce capability (ie it swivels in different directions). Even though VR/IS and sensor noise improvements have made working in low light easier than in the past, sometimes there's just no substitute for having more light in your bag. The bounce capability is nice for indoors where you can use the flash (pointing at the ceiling) to evenly light the room and avoid the deer-in-headlights look on your subjects. It's also nice to have something a bit more robust than the built-in flash when trying to illuminate backlit subjects (such as in front of a sunset or whatever) or for use as fill flash in harsh sunlight. Canon and Nikon both have good offerings in the 100US range. You can live without it starting out, but don't underestimate the value of having one going forward.
In so far as landscapes/scenery, the kit lens will be an okay start; you'll probably have to deal with a bit of barrel distortion at the wide end which can usually be dealt with in software. Depending on the camera you settle on, processing software might come bundled (though most people would say invest in Adobe Lightroom, although there's some good open source options like RawTherapee and Darktable). But if you're even a little serious about it (such as taking long exposures of bodies of water, high dynamic range composites, etc), expect to invest in a dedicated wide lens, a tripod and neutral density filters at some point. Don't skimp too much on the tripod system--it's arguably as an important an investment as the camera and lens. It's also worth remembering always that everything with photography involves compromise and most purchasing decisions can be summarized in the "lightweight-quality/sturdy-cheap, pick two" triangle. Not to overwhelm or get ahead, only to point out that photography as a hobby can be a real moneypit, and the industry is built on incremental upgrades designed to get you to spend twice as much as you really need to get where you want to be, so being wary of that can save you some grief going forward as you plan out your path (should you desire to move beyond the starting point).