The above post is a good one. Here is what I would add:
- Go to HD or Lowes and buy a bottle of Weed-B-Gone that attaches to the end of your hose or a similar product that has 2,4-D and Dicamba. Spray your whole yard.
- Wait 2 or 3 days and then mow
- 2-4 days after mowing the grassy weeds in your yard will be shooting up above your bermuda because it really isn't growing yet
- Go back and buy some Image or look for/ask for a product with a sulfnylurea active ingredient and either spot treat or broadcast spray your grassy weeds.
The weeds you see right now are all "Winter Annuals" the Weed-B-Gone will take care of the broadleafs. You may have a few more pop up, but you can get a spot sprayer and take care of those. Any grassy weeds you have now are also "Winter Annuals". Whatever you spray on them will not kill them quickly, but in the course of a month - with a herbicide app and a couple of mowings - they will all die
I don't subscribe to the need to scalp. Mow your yard a little lower in increments. Say if you mow the first time at the 3rd or 4th notch on your mower, go down one the next time, and then one more the next time. I try to start the year on the first notch of my mower knowing that with bermuda will have to raise the height has the year goes on.
Go ahead and put a preemergent down as soon as possible as well. I know the big box stores sell a Lesco 0-0-7 with PreM - pendemethlin. If you can find one with Dithyiopir as the active ingredient you will have better results. Right now, you are preemerging for crabgrass and other summer weeds that have not germinated, but will be soon.
In Dallas, you really need to preemerge 4 times a year - March 1, June 1, Sept 1, and Jan 1- if you want to really reduce your weeds. As the poster above said, a healthy yard is the best preemergent. Most people/lawn services will skip the Jan 1 preemergent application which is why there are so many weeds right now. The weeds you see now are easy to kill hence why most services skip that Jan 1 app.
With just a little bit of effort on your part you can eliminate/greatly reduce your weeds for a fraction of what the services charge and do a better job.
Let me know if you have any questions. I've been a Golf Course Superintendent for 20+years and have a really small landscaping service in the Frisco area if you need help.