Latvia is still operating the stock that was inherited on independence, though some of the EMUs have been radically refurbished.
Service on most lines has been muich reduced. Outside the Riga suburban electric system, most lines only see a couple of trains per day. Some even less Liepaja (third largest city in the country) only has two trains per week ! All internal services are run by either the ER2 family of EMUs or DR1 Family of DMUs. The only loco hauled passenger trains are the overnight ones to Moscow, St Petersburg or Minsk (?), which use TEP70s.
Freight traffic is predominately transit traffic from Russia / Belarus to the ports of Liepaja and Ventspils. These use classes M62, 2M62 and 2TE10. All such traffic must cross either the main river bridge at Riga, or go through Jelgava. Krustpils (where the routes divide) is also a good place for freight. The main freight yards and depot in Riga are on the line to Krustpils / Daugavpils. There is a footbridge next to Daugmale station from which you can see most action. Main loco works are in Daugavpils, where you can also see locos from Belarus and Lithuania (not sure how frequent these are though).
There is one narrow gauge line in use, from Gulbene to Aluksne. There are two trains per day normally TU2 diesel loco, but they may have finished restoring a steam loco (on loan from museum in Estonia). Steam would only be used on special workings anyway. On summer Saturdays there is a special train from Riga to Gulbene which allows you to do a round trip to Aluksne. Gulbene is very difficult to get to otherwise.
There is also a preserved section of ex Feldbahn line in a park at Ventspils.
There is a small railway museum in Riga check opening hours before visiting. Latvian Railways has two preserved L class 2-10-0s which are occasionally used on special trains.
Riga has large tram and trolleybus fleets. The tram fleet is a mixture of brand new Skoda T15 and ancient (but refuirbished) Tatra T3 and T6. The trolleybus fleet is almost completely modernised, mainly Skoda / Citelis 24Tr and Solaris Trollino18, but still a few old Skoda 14Tr / 15Tr.
There are also tram systems in Daugavpils and Liepaja. Daugavpils has 3 routes, and is the last place in the world still using RVZ trams, also KTM5 and ex German Tatras. [They are reported to have ordered new trams from St Petersburg] Liepaja has only 1 route and is 100% operatedby Tatra KT4.
Sigulda has the gaiss tramvajs (literally air tramway) a cable car across the Gauja river valley.
Riga has a very standardised bus fleet. Mainly Solaris and Citaros of various lengths, plus some Ikarus E91 midibuses and Mercedes O345.
As for eating / drinking establishments in Riga, a very good guide can be found at
www.inyourpocket.com My own personal recommendations are the Alus Seta (best pub in the world
http://www.lido.lv/eng/companies/catering_companies/alus_seta/ ), the Brevinga ALus and Viskej Bar (next door), Citi Laiki, Petergailis cafe, and the beer gardens in the three main squares of the old town (good music most nights).