Welcome to the exciting world of genealogy. You will need lots of patience, creativity and flexibility.
If you are just starting, I strongly suggest you spend some time reading the tutorials in Ancestry.com's Learning Center (box at top of screen). FamilySearch.org (LDS) has a good site too and has lots of info how to find ancestors.
After doing some basic research as suggested above, I advise interviewing all living relatives you can get to talk. Even a seemingly old "family fairy tale" usually has some truth to it. Once you get relatives talking they inevitably think of some nugget about who married who, etc. Write it all down, even if you suspect it's bunk. Jog memories of older relatives by asking about old Christmas memories, 4th of July get-togethers, etc. Ask if you can make copies of old photos & have the person ID who's in the picture, best guess of date & where taken.
Where to post on these boards? Try to pick a category that most closely fits your question. If you have a surname you're researching, post under the Surname board vs a State/County board. If you have a question about finding info in a particular area, posting under the appropriate county is usually the best.
The more specific your question, the more likely you are to get an intelligent, helpful reply. Keep questions short but include pertinent info. If question is about a person or family, always include FULL name(s), best guess of year born (you can always write "c 1960"; "c"=circa/about), where born (at least a state or country if not in US)., any known nickname, where found ancestor last or where known to have lived. Other helpful info would be name(s) of parents, siblings, spouse, etc. It's best not to ask for "any info on XXXX". Many posters ignore questions asking for "any" as too many people post that then you find out they already have a ton of stuff & wanted something very specific. No one likes being sent off on a wild goose chase. Don't ask for things you can easily look up yourself via Google; i.e "who knows what county Detroit is in?" or "where can I contact the main library in Atlanta?". I know this sounds basic but you'd be shocked at the fool questions people ask. I've seen posts saying nothing but "Who can tell me who my grandfather was?" Duh!
A good "subject" line attracks posters. If you're on the Ross Surname page, don't say "seeking Ross ancestors"; everyone on that page is doing that. Say, for example:
"Seeking ROSS, David b c1880 PA Jane Doe b 1885 OH"
Specifically regarding "hints" I personally don't rely on them too much. I've been doing genealogy for over 20 yrs (before so much was on-line). I've noticed that over the last year or so "hints" have been getting stretched thinner thus having less viability. For me, I've found "hints" on common names to be less than helpful.
You might want to start using paper and pencil to get down the "base" family then move onto a genealogy software program. I use Family Tree Maker (FTM) & can only comment on that software. I assume other brands have similar features. FTM has places to document each piece of info (i.e. list a source). It becomes kind of a "one stop shopping" source for reviewing all info you've accumulated on an individual.
For a long time after I got on-line & starting using FTM, I used a spiral notebook (like one for high school, one subject thick) and documented where I found every sliver of info. I used one notebook per family group or surname. You will be surprised how often in the future you will need to look back at a source. Sometimes once you get a good amount of info on an ancestor you may well re-interpert that odd-ball piece of info you found years ago. It's very irritating to not be able to locate where you found something years ago!
One other thing to learn before you get too involved. For each geographic area you are searching, you should try to learn about where that area kept/keeps it's records, how long they have had records (especially birth/death/marriage). Did they leave it up to the church(es) to keep or did a Town Hall keep them? Does the local library (in area you are searching) have a genealogy dept? Many libraries have town history info & are very accommodating via email. Also ask the library about where old newspapers are stored, how far back they go & how one accesses them. Find out when the state(s) you're researching became a state. Find out if the county and town changed names/merged, etc. If your ancestors lived in a border community (i.e. in PA but on WVA line) be sure you look in both states. Sometimes people didn't physically move but the town changed counties and/or states. In the PA vs W VA example for instance, W VA was part of VA until the Civil War, when it became W VA. PA had a habit of bickering with border states over state lines. This is not uncommon. All states & municipalities have different practices. The more you learn about an area, the less likely you are to spin your wheels & pull out your hair.
Lastly, take your time. Quality is far superior to quantity. DON'T assume anything you see in writing is 100% accurate. There are errors everywhere, even in original documents. Just because someone posted a tree on Ancestry.com or elsewhere doesn't mean they did the research themselves (many just copy & paste someone else's work). Without doing the research yourself, you don't know the quality or if someone took a wrong turn somewhere.
Enjoy yourself, the journey is just as much fun as building an accurate family tree. Best of luck. Enjoy!
(common abbrviations used: b=born, d=died, m=married, c=circa)