I would read this first. Tripods
If you buy a cheap tripod, you will not like the tripod and tend not to use it. A tripod is supposed to give you a steady support. Good tripods do give sturdy support and cheap tripods are sometimes worse than no tripod at all. A tripod does more than support weight, it also dampens vibration. At the very minimum, I would recommend a Bogen (Manfrotto). I used a Bogen 3221 for 8 years and still have it. I upgraded the Bogen ballhead with a Markins M20 and could not believe the difference the Markins made. I then upgraded the Bogen to a Gitzo G1325. The Bogen is aluminum and the Gitzo is Carbon Fiber. The Gitzo absorbs vibrations much better than the Bogen and my photos are sharper as a result. I am the kind of person that uses a tripod for everything unless tripods are not allowed, then I use a monopod. I only shoot handheld with my 18-70 lens. Anything larger goes on the tripod or monopod. I also use a Wimberely sidekick on the Markins/Gitzo combination for my dog agility action shots. It makes my 80-200 or my 300 lens float. You have to try one to understand!!