We are planning a trip to paris then to Allicante Spain. Where is the best place to stay in order to be central to the Eifel tower and the Seine river area? If you know of any good clean Hotels and good innexpensive restaurants in that area would also be helpful to us. We would like to spend 3 or 4 days in Paris then go to Provence, Cote D'Azur by train, then leave from there by train and head of to Allicante Spain. We plan on leaving mid October.
Thanks

The Seine river runs through the entire city of Paris - you can't escape being central to it unless you choose a very southern or northern arrondissement. Central to the Tour Eiffel would be most likely the 7ème arrondissement. I doubt there are any dirty hotels in that neighborhood. There aren't many inexpensive restaurants either, but not knowing what your definition of inexpensive is, it's impossible to make recommendations.

I would suggest getting a guidebook and a map of Paris to start with to get your bearings.

Have you given this adventure a lot of thought? Mid-October is only 4 weeks away.

Do you have a budget in mind for your Paris hotel?

You can go by train from the Cote D'Azur to Alicante, but it can take a while, up to 30 hours travel time, and you'll be changing trains 4 to 6 times along the way, depending on the route you choose.

The Eiffel Tower area is not considered all that central, compared to the Notre Dame-Louvre-Latin Quarter area.

October is a pretty busy hotel period in Paris, you had better start looking to book a room. Paris is a very large city, and has many hotels that could fit your criteria but before people spend their time making suggestions, it would narrow things down if you stated a budget. I suspect low since you mention the clean issue, but am not sure.

Here is a nice hotel that is in the same general area as the Eiffel Tower but isn't near the Seine. It is very clean.
http://www.hotelparismuguet.com/

If you really want to be near the Seine, you shouldn't stay in the area where the Eiffel Tower is, but the area near Notre Dame.

You need a street map of Paris. As mentioned the river runs thru most of the city! The Eiffel Tower is in the 7th arrondisement but that's not really considered "central" (which would be 4, 5, 6).

You can look for hotels in the 15th arrondissement that are within walking distance of the Eiffel Tower, such as http://www.beaugrenelleparis.com/location.html , but I would not consider such establishments close to other tourist sites.