How important to write good English (or in good English)

One of the challenges of the vacation rental site that I run - my English. We don't have a phone number listed yet on Vacation Rentals Listed but I already imagine what will happen once it is there. I do have very distinctive accent. Some people find it cute, some find it beautiful and some will not understand me at all. I am learning now on how to write. Or at least on how to "not write".
Main challenge of Russian speaking people with English
1.the order of words. We have absolutely no "order" system in Russian sentences. As funny as it might sound, we can say "I want to rent vacation home" as
- Vacation home I want to rent
- I want vacation home to rent
- Vacation home to rent I want
so I always have to be alerted and build my sentences in right order.
2. A, THE and all around
The theory is simple. If this is something determined, we say THE, otherwise we say A (AN). On practice it is not easy at all.
3. Times - past, present, continued past (what?)....
I have booked vacation rental
I had booked vacation rental
I booked vacation rental
They look all the same to me :). Now you know why I need to imporove my grammar.