Ok, to me this seems like a complicated question, but hopefully someone will be able to give me some advice. I bought a home (over 100 years old), and a few months later we were having leaking from the base of our guest bathroom, dirty icky water coming up through the tubs, and the master toilet gurgled whenever the shower was running or washer was running.
Paid to have a plumber come and find the problem. He ended up snaking the guest toilet, pulling up lots of old nastiness and tree roots. We thought the problem was solved after all that time and money.
A few months later, which happens to be this week, now we are experiencing the same thing (water backing up in both bathroom tubs, and now BOTH toilets gurgle when the shower is running or washer is running).
I have no clue what the problem is... it's an old home, and it's getting to be winter time (although it has also been raining all week!)... I need some help. We really can't afford to have a plumber out again to do the same thing over again and not have it help for more than a few months!

If the snake helped and this turns out to not be a serious problem (which it could be because of the recurring events) I would buy a snake and simply learn how to work it yourselves. It might be expensive (not sure) but if this happens again, it will be worth it at that point. However, I'd have someone look at it. It could be a problems with your pipes themselves or something even worse. The system may not have been updated as time went by and you could very well be working with a very old system that simply isn't up to today's standards. I'm sorry for scaring you if it isn't this serious. It may just be something like your pipes aren't suitable for the bigger things we flush down toilets today like huge wads of toilet paper and tampons. Also, do you have kids? This causes strange objects to appear in weird places at times.

We were thinking of buying a snake or renting one, but I am a little paranoid about messing with those things, and opted to get a "professional" to our home ASAP. Well, the first day he came out he spent the whole time looking around outside and asking me questions I didn't have answers to. He said he would have to come back the next day with "help." The help was another guy who stood and watched as he snaked the toilet. Now I think that we could have done this ourselves.
I really don't know if it is serious or not; I am a first-time home owner and know absolutely nothing about stuff like this. And for the record, no one in the household puts anything other than toilet paper in the toilets... my mother taught/threatened me long ago not to do that (haha). And no, no kids either, so no little toys or things should surprise us being clogged in there.
I also surfed the net and found other similar questions about this problem (not the same, but similar) and most of the solutions pointed to problems in venting. No clue what this is or where to find it or fix it... but it sounds like something to maybe look into.
Also, if it is an issue of old, outdated pipes, do I call a regular plumber or are their "specialists." I hate being ignorant about these things... thank you for your advice!