Honeymoon in October

I would say that 9 days would be as good as 11 days but cheaper in terms of accommodation - so you can spend the money for some really exciting (but not so cheap) tour like ... helicopter tour.

Try to "pack" your days as full as possible because days are short in October.

And yes, you can incorporate your things very easily. The good thing are - car rental cheaper and easy to find place to stay overnight during that period.

Petrol costs the same +/- 10-20% all over Europe.
Car rental companies have a minimum age higher than 18 and sometimes a intermediate bracket where the insurance costs extra.

Remember that time of year you are likely to get a certain amount of terrible weather, so you can't always do things just when you want to. The best thing in Iceland is to be flexible so you can take alter your plans according to the weather. Also going around the ring road at that time of year there is the possibility of some occasional delays due to wintry weather, (though in all likelihood you'll see more rain than snow) so a bit of time in hand to recover from delays is a good idea.

More time is always good in Iceland. And remember you are on your honeymoon, you probably don't wan tot be driving on everyday, but 1350km around the ring road, plus detours to see stuff, can add up to quite a grind if you are doing it too quickly.

Thank you for all the advice. I am leaning towards going for 11 days because I rather take a more leisurely time around the ring road. We can offset the cost by maybe camping out on one of the nights. Is this something people do? I would love to camp out under the stars on a night. I also think we will want to visit the Blue Lagoon on our last day before heading out so that effectively gives in 10 days to do the Ring Road.

Are there any suggestions as far as hotels or places to stay along the road and the most cost effective place to rent a car? Also, are the guided tours worth it or should we go on our own? We would love to visit caves and waterfalls along the way. Is there a good book that can guide us on what to see? Thank you all once again.

In terms of car rental I can recommend two places. I have used them both and found them to be excellent value.

http://www.islandiacar.com/
http://www.carsiceland.com/

In terms of camping I wouldn´t recommend it in October. Camping is very popular in Iceland in summer but in October it can get very cold at night. As an alternative you could try the youth hostels for cheap (and dry) accommodation..

http://www.hostel.is/

If you are going to rent a car then I wouldn´t bother with the guided tours, a lot of Icelands popular sites are easily accessible in a 2WD.

Well we offer you our own vehicles or find the BEST DEAL on the car rental market for you.
Cars Iceland is a unique booking center because we search out the best price in the market ...Cars Iceland´s staff has an intimate knowledge of Iceland

So both are not very really car rental companies.

My favorite is bluecarrental.is - right cars at right prices (always check insurance cost!)

I rented from North Car Rental this month and was happy about prices and service. No extra charges for pickup at airport and drop off in Reykjavik.

I stayed at several airbnb places around the Ring as well as hotels. Airbnb was better.

I apologize for not responding. Last minute wedding planning has swamped me. I appreciate all the suggestions. I am actually looking to switch the trip up a little bit. Instead of doing the Ring Road, I am looking to concentrate on the South and West parts of Iceland instead and spend the last two nights in Reykjavik. Is there a city in the South where I could base my trip from and make day trips to the waterfalls, hot water springs and best hiking routes? I could potentially spend 3-4 nights in Vik and make day trips from there and then spend 3 nights in another city before heading back up to Reykjavik. Do you have any suggestions as far as hotels or places that could serve as good base camps for the trip? Thank you so much once again!