I have filed multiple trademarks in the US by myself without a lawyer, it is not particularly difficult.
My advise would be to stay away from "edge cases" where there is high likelihood of a problem such trying to trademark a hamburger as a "MacTripple" (McDonalds has the McDouble) or a soft drink as "Koke" (CocaCola).
You need to also understand that if someone is already using the same name you want and has not trademarked it, you will probably still get the trademark, but that other person can continue to use the name (because of prior use rules) and you can't stop them.
The case that will work best for you is if you can think up a strong mark (Google the term) such as a completely made up word that has seldom or never been used before. If you can put your new word into Google and do a search with no results then there is a really good chance that you will not conflict with anyone. Examples of such marks are Exxon and Xerox (which are made up and had never been used before).
Also register the domain name ASAP as you do not want to go to the trouble and expense of filing the trademark application and find out someone else grabbed the domain name the day after you filed for the trademark. You would probably win, but remember your original goal of not having to pay lawyers a lot of money; avoid problem areas.
A tip on filling out the forms: You will need to pick a category for your product. You can file for multiple categories, but each category involves and additional fee so you probably want to pick just one. It is important to understand that two different firms can use the same name (Cadillac dog food and Cadillac cars. Apple records and Apple computers).
Now if you have a strong mark (which Apple and Cadillac are not, apple being a fruit and Cadillac a French explorer), and have registered the domain name, then I would not worry too much about picking the perfect category. Just pick one that seems like the best fit.
Finally what I have told you is my experience in the US, every country has unique rules and if you are operating internationally and want trademark protection in multiple countries then you will probably need multiple lawyers to cover the various quirks.
I've never attempted it myself, but I've heard that unlike patents, it is possible to file for a trademark without a lawyer. However, it may require time investment you may not have, or be willing to give up.
If you want to try it yourself, I would suggest reading the book Trademark by Nolo. I've read several Nolo books and they were all very good and informative. My guess is that with the help of that book you should be able to do it on your own. At the very least after reading it you should be able to assess for yourself if it is something you can, or want to, do yourself. $27 is a small investment for the chance of being able to save $3K. Tip: Check your local library first. I've found a lot of Nolo books at my local library.
Another possible book to check out is Patent, Copyright & Trademark: An Intellectual Property Desk Reference.
Hope that helps. Come back and let us know what you end up doing.
I routinely refer my clients to Tom Philbrick (email@example.com), who specializes in trademark registration.
Tom's standard fee is a fraction of what your firm wants to charge. It is worth paying to avoid the significant likelihood of a mistake if you file the registration yourself.
If you insist on doing it yourself, I agree that Nolo publications can be quite helpful.
Disclaimer: This information does not constitute legal advice and does not establish an attorney-client relationship.