I have to agree with Joe and Andy,
If you are a professional photographer with a sucessfull business then you should know that we can't tell you what to charge ... we don;t know your business operating costs, what type of profit margin you are looking for, we don;t even know what you package includes and what your won costs for that package is (prints, time travel, assistants ...).
I have serious doubts about you being an acutal pro.
The next point of contention here is your affirmation that you'll be shooting with with a crappy 18-135 ... that thing is far too slow for low lighting normally found in churches and reception halls. Where is your L glass (or equivalent)? I shoot with 2 cameras on me. One with a 24-70 f2.8 and the other with a 70-200 f2.8.
"Equipment costs will be taken in to account ..."
What does this even mean? You charge your client vbased on the gear you are usin for the shoot? That's not how you build your costing ... it doesn't make sense unless you mean rental costs?
As far as what to charge ... add up your business operating costs (studio rent, cellphone, web hosting, domain name registartion, liability insurance ... so on so forth), divide that by the number of shoots you plan on doing in the year and that is your first cost.
you next cost is to add up YOUR cost for the shoot itself (cost of prints, albums, gear rental, assistant salary ... so on so forth).
Next, determin how much work this shoot represents (in hours. meeting clients, prepping, travel, shooting, backing up, post processing, ordering prints ... so on so forth) decide how much you want to be paid per hour (12$, 20$, 30$ an hour ... whatever) and multiply the two.
Add all 3 amounts and oyu have what you should be charging.
=========
EDIT
=========
You said:
"thank you to the last answer which i found much more helpful :) although i do not claim to be a pro...i'm just somebody trying to set themselves up a career in the photography business. yes i did mean rental costs when i said about equipment."
but before that you said:
"i'm not a beginner photographer and i get paid for all other areas of photography, but i have not done much in the area of wedding photography before."
A definition of "professional" follows:
"A professional is a person who is paid to undertake a specialised set of tasks and to complete them for a fee."
Wikipedia: http://en.wikipedia.org/wiki/Professional
"Following an occupation as a means of livelihood or for gain: a professional builder."
"following as a business an occupation ordinarily engaged in as a pastime: a professional golfer."
Dictionary.com: http://dictionary.reference.com/browse/professional