I'll be in SA at the end of April for a conference. Any recommendations on where to stay, what to eat, stuff to do?
Been there about 35 times. City covers large area so I would stay near your conference otherwise you may drive 30+ minutes if you stay at River Walk and conference is by the airport or vice versa.
If you stay down by the river walk, the Hilton ground floor empties onto the river walk and higher floors have nice views. But I preferred the Emily Morgan hotel or Hotel Havana.
For food, lots of choices. The river walk does have a few good restaurants, but IMO, many are overpriced as you are paying a premium for the location. But on river walk, I'd consider Luke, Little Rhein Steakhouse, Boudro's, Biga's on the Banks. Others downtown, Texas de Brazil on Houston (near Alamo) is my favorite Brazilian Steakhouse downtown and Bohanons (prime steak). Ticket Sports bar near Alamo is only place in U.S. that I could find my favorite beer from when I lived in Germany called Krombacher. Go have one after seeing the Alamo if you like a good pilsner.
A great Brazilian place up north of town is Chauma Gaucha. Pappasitos is great tex-mex great for groups. Grey Moss is romantic prime steak place where they cook outside over wood fire and can eat outside in nice setting. It is northwest of town. Surprisingly, I found a good sushi place not to far from airport called Godai Sushi Bar. Thai Dee is my favorite thai place that I found there. Nothing fancy but good. Taco Cabana is a must if you like to have a cold beer at local chain tex-mex fast food. I've had my share of bad food in San Antonio but the list above are places I have gone back to because I liked them.
As far as things to do, depends on how much time you have and whether you have car, etc.
The Missions outside of town (after seeing the Alamo) are worth seeing. But you can take a full day getting to them and seeing them. If you go to Fredericksburg, I would try to go further to Enchanted Rock if you like to hike. Not a hard hike but gives great view. Boerne is cool little downtown. The River Walk has a boat guided tour. It looks corny, but it is worth doing as they give history and guides are usually entertaining. If you have time to get to Austin, lots of live music and pubs on 6th street. I enjoyed the LBJ museum more than I thought I would.
For golf, the Quarry is ok as someone mentioned, but I think it is overpriced. I prefer the Republic.
Hope that helps.